exp/locale/collate: add code to ignore tests with (unpaired) surrogates.
In the regtest data, surrogates are assigned primary weights based on
the surrogate code point value.  Go now converts surrogates to FFFD, however,
meaning that the primary weight is based on this code point instead.
This change drops tests with surrogates and lets the tests pass.

R=r
CC=golang-dev
http://codereview.appspot.com/6461100
math/big: faster (add|sub)V(V|W) routines

Benchmarks run on 3.06GHz Intel Core 2 Duo,
4GB 800MHz DDR2 SDRAM ("iMac").

benchmark             old ns/op    new ns/op    delta
BenchmarkAddVV_1              6            6   +2.75%
BenchmarkAddVV_2              9            7  -19.71%
BenchmarkAddVV_3              9            9   +2.25%
BenchmarkAddVV_4             10            8  -20.46%
BenchmarkAddVV_5             12           10  -19.53%
BenchmarkAddVV_1e1           23           15  -32.48%
BenchmarkAddVV_1e2          213          107  -49.77%
BenchmarkAddVV_1e3         2088          993  -52.44%
BenchmarkAddVV_1e4        20874        12027  -42.38%
BenchmarkAddVV_1e5       209858       121480  -42.11%
BenchmarkAddVW_1              5            5   +0.90%
BenchmarkAddVW_2             11           11   -3.51%
BenchmarkAddVW_3              7            7   -0.27%
BenchmarkAddVW_4              8            7   -6.32%
BenchmarkAddVW_5              9            8  -10.89%
BenchmarkAddVW_1e1           17           12  -26.01%
BenchmarkAddVW_1e2          155           89  -42.32%
BenchmarkAddVW_1e3         1479          873  -40.97%
BenchmarkAddVW_1e4        13838         8764  -36.67%
BenchmarkAddVW_1e5       147353        89560  -39.22%

benchmark              old MB/s     new MB/s  speedup
BenchmarkAddVV_1        9765.57      9508.55    0.97x
BenchmarkAddVV_2       13077.63     16284.97    1.25x
BenchmarkAddVV_3       20599.58     20156.67    0.98x
BenchmarkAddVV_4       23591.58     29516.02    1.25x
BenchmarkAddVV_5       24920.95     31194.10    1.25x
BenchmarkAddVV_1e1     27393.76     40621.71    1.48x
BenchmarkAddVV_1e2     29911.96     59592.99    1.99x
BenchmarkAddVV_1e3     30650.73     64429.84    2.10x
BenchmarkAddVV_1e4     30660.09     53213.08    1.74x
BenchmarkAddVV_1e5     30496.74     52683.46    1.73x
BenchmarkAddVW_1       11503.39     11405.98    0.99x
BenchmarkAddVW_2       11203.56     11586.92    1.03x
BenchmarkAddVW_3       26173.45     26224.75    1.00x
BenchmarkAddVW_4       30560.30     32621.94    1.07x
BenchmarkAddVW_5       33183.81     37269.94    1.12x
BenchmarkAddVW_1e1     36991.75     50098.53    1.35x
BenchmarkAddVW_1e2     41087.14     71549.93    1.74x
BenchmarkAddVW_1e3     43266.42     73279.83    1.69x
BenchmarkAddVW_1e4     46246.74     73021.97    1.58x
BenchmarkAddVW_1e5     43433.00     71459.96    1.65x

Benchmarks run on 2.8GHz Quad-Code Intel Xeon,
4GB 800MHz DDR2 FB-DIMM ("PowerMac").

benchmark             old ns/op    new ns/op    delta
BenchmarkAddVV_1              7            7   +2.51%
BenchmarkAddVV_2              8            8   +3.70%
BenchmarkAddVV_3             10           10   +4.00%
BenchmarkAddVV_4             11            9  -19.49%
BenchmarkAddVV_5             14           11  -18.44%
BenchmarkAddVV_1e1           23           17  -27.00%
BenchmarkAddVV_1e2          234          117  -50.00%
BenchmarkAddVV_1e3         2284         1095  -52.06%
BenchmarkAddVV_1e4        22906        13149  -42.60%
BenchmarkAddVV_1e5       229860       135133  -41.21%
BenchmarkAddVW_1              6            6   +1.15%
BenchmarkAddVW_2              7            7   +1.37%
BenchmarkAddVW_3              7            8   +1.00%
BenchmarkAddVW_4              9            8   -6.93%
BenchmarkAddVW_5             10            9  -13.21%
BenchmarkAddVW_1e1           18           14  -24.32%
BenchmarkAddVW_1e2          170           97  -42.41%
BenchmarkAddVW_1e3         1619          953  -41.14%
BenchmarkAddVW_1e4        15142         9776  -35.44%
BenchmarkAddVW_1e5       160835       102396  -36.33%

benchmark              old MB/s     new MB/s  speedup
BenchmarkAddVV_1        8928.95      8702.84    0.97x
BenchmarkAddVV_2       15298.84     14739.60    0.96x
BenchmarkAddVV_3       19116.52     18375.37    0.96x
BenchmarkAddVV_4       21644.30     26935.44    1.24x
BenchmarkAddVV_5       22771.64     27754.04    1.22x
BenchmarkAddVV_1e1     27017.62     37050.89    1.37x
BenchmarkAddVV_1e2     27326.09     54289.15    1.99x
BenchmarkAddVV_1e3     28016.84     58428.83    2.09x
BenchmarkAddVV_1e4     27939.38     48670.55    1.74x
BenchmarkAddVV_1e5     27843.00     47360.54    1.70x
BenchmarkAddVW_1       10510.97     10397.27    0.99x
BenchmarkAddVW_2       17499.71     17279.03    0.99x
BenchmarkAddVW_3       24093.93     23858.39    0.99x
BenchmarkAddVW_4       27733.08     29799.42    1.07x
BenchmarkAddVW_5       30267.17     34781.83    1.15x
BenchmarkAddVW_1e1     34566.78     45629.88    1.32x
BenchmarkAddVW_1e2     37521.89     65341.93    1.74x
BenchmarkAddVW_1e3     39513.18     67153.67    1.70x
BenchmarkAddVW_1e4     42263.80     65464.60    1.55x
BenchmarkAddVW_1e5     39792.21     62501.88    1.57x

R=iant, remyoudompheng, nightlyone, minux.ma
CC=golang-dev
http://codereview.appspot.com/6482062
math/big: minor tweaks to assembly code (slightly better performance)

Benchmarks run on 2.8GHz Quad-Code Intel Xeon,
4GB 800MHz DDR2 FB-DIMM ("PowerMac").

benchmark             old ns/op    new ns/op    delta
BenchmarkAddVV_1              7            7   -0.82%
BenchmarkAddVV_2              8            8   -3.46%
BenchmarkAddVV_3             10            9   -4.81%
BenchmarkAddVV_4              9            9   -1.89%
BenchmarkAddVV_5             11           10   -5.22%
BenchmarkAddVV_1e1           17           18   +4.05%
BenchmarkAddVV_1e2          117          115   -1.71%
BenchmarkAddVV_1e3         1095         1090   -0.46%
BenchmarkAddVV_1e4        13149        12679   -3.57%
BenchmarkAddVV_1e5       135133       129482   -4.18%
BenchmarkAddVW_1              6            6   -1.14%
BenchmarkAddVW_2              7            7   +3.78%
BenchmarkAddVW_3              8            8   +0.12%
BenchmarkAddVW_4              8            8   -6.52%
BenchmarkAddVW_5              9            8   -3.70%
BenchmarkAddVW_1e1           14           13   -4.29%
BenchmarkAddVW_1e2           97           96   -1.33%
BenchmarkAddVW_1e3          953          940   -1.36%
BenchmarkAddVW_1e4         9776         9527   -2.55%
BenchmarkAddVW_1e5       102396        97738   -4.55%

benchmark              old MB/s     new MB/s  speedup
BenchmarkAddVV_1        8702.84      8774.56    1.01x
BenchmarkAddVV_2       14739.60     15277.82    1.04x
BenchmarkAddVV_3       18375.37     19398.16    1.06x
BenchmarkAddVV_4       26935.44     27464.68    1.02x
BenchmarkAddVV_5       27754.04     29423.30    1.06x
BenchmarkAddVV_1e1     37050.89     35629.72    0.96x
BenchmarkAddVV_1e2     54289.15     55533.24    1.02x
BenchmarkAddVV_1e3     58428.83     58682.53    1.00x
BenchmarkAddVV_1e4     48670.55     50475.99    1.04x
BenchmarkAddVV_1e5     47360.54     49427.66    1.04x
BenchmarkAddVW_1       10397.27     10502.23    1.01x
BenchmarkAddVW_2       17279.03     16654.13    0.96x
BenchmarkAddVW_3       23858.39     23825.89    1.00x
BenchmarkAddVW_4       29799.42     31895.06    1.07x
BenchmarkAddVW_5       34781.83     36105.11    1.04x
BenchmarkAddVW_1e1     45629.88     47597.42    1.04x
BenchmarkAddVW_1e2     65341.93     66240.04    1.01x
BenchmarkAddVW_1e3     67153.67     68069.83    1.01x
BenchmarkAddVW_1e4     65464.60     67173.83    1.03x
BenchmarkAddVW_1e5     62501.88     65480.66    1.05x

R=iant
CC=golang-dev
http://codereview.appspot.com/6484056
text/template: allow grouping of pipelines using parentheses

Based on work by Russ Cox. From his CL:

        This is generally useful but especially helpful when trying
        to use the built-in boolean operators.  It lets you write:

        {{if not (f 1)}} foo {{end}}
        {{if and (f 1) (g 2)}} bar {{end}}
        {{if or (f 1) (g 2)}} quux {{end}}

        instead of

        {{if f 1 | not}} foo {{end}}
        {{if f 1}}{{if g 2}} bar {{end}}{{end}}
        {{$do := 0}}{{if f 1}}{{$do := 1}}{{else if g 2}}{{$do := 1}}{{end}}{{if $do}} quux {{end}}

The result can be a bit LISPy but the benefit in expressiveness and readability
for such a small change justifies it.

I believe no changes are required to html/template.

Fixes issue 3276.

R=golang-dev, adg, rogpeppe, minux.ma
CC=golang-dev
http://codereview.appspot.com/6482056
text/template: catch (A).X as a parse error
This shouldn't be an error (see issue 3999), but until it's handled
correctly, treat it as one to avoid confusion. Without this CL,
(A).X parses as two arguments.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/6473059
VERSION: check in a version file for the development branch
That way "go version" will talk about "devel" rather than weekly.2012-03-27

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/6478061
math/big: fix broken comment

R=iant, iant
CC=golang-dev
http://codereview.appspot.com/6485064
test: use run.go for more tests.

R=golang-dev, alex.brainman, minux.ma
CC=golang-dev
http://codereview.appspot.com/6443110