runtime: update openbsd thread related syscalls to match kernel

Update the threxit and thrsleep syscalls to match the ABI of the
OpenBSD 5.1 kernel. These changes are backwards compatible with
older kernels.

Fixes issue 3311.

R=golang-dev, rsc, devon.odell
CC=golang-dev
http://codereview.appspot.com/5777079
runtime: add interface microbenchmarks

2011 Mac Mini, Core i5 @ 2.3Ghz

BenchmarkConvT2E        50000000                40.4 ns/op
BenchmarkConvT2EBig     20000000               107 ns/op
BenchmarkConvT2I        100000000               28.9 ns/op
BenchmarkConvI2E        500000000                5.93 ns/op
BenchmarkConvI2I        100000000               19.0 ns/op
BenchmarkAssertE2T      100000000               14.1 ns/op
BenchmarkAssertE2TBig   100000000               17.8 ns/op
BenchmarkAssertE2I      100000000               21.3 ns/op
BenchmarkAssertI2T      100000000               14.3 ns/op
BenchmarkAssertI2I      100000000               20.8 ns/op
BenchmarkAssertI2E      500000000                5.58 ns/op

Pandaboard, 2 x Omap4 @ 1.2Ghz

BenchmarkConvT2E        10000000               215 ns/op
BenchmarkConvT2EBig      1000000              3697 ns/op
BenchmarkConvT2I         5000000               666 ns/op
BenchmarkConvI2E        50000000                42.4 ns/op
BenchmarkConvI2I         5000000               489 ns/op
BenchmarkAssertE2T      20000000                90.0 ns/op
BenchmarkAssertE2TBig   20000000                91.6 ns/op
BenchmarkAssertE2I       5000000               515 ns/op
BenchmarkAssertI2T      20000000               124 ns/op
BenchmarkAssertI2I       5000000               517 ns/op
BenchmarkAssertI2E      50000000                47.2 ns/op
BenchmarkAssertE2E      50000000                42.7 ns/op

R=minux.ma, rsc, fullung, bsiegert, dsymonds
CC=golang-dev
http://codereview.appspot.com/5777048
exp/norm: exposed runeInfo type in API.
For completeness, we also expose the Canonical Combining Class of a rune.
This does not increase the data size.

R=r
CC=golang-dev
http://codereview.appspot.com/5931043
crypto/tls: update how we create testing scripts.

crypto/tls is tested, in part, by replaying recorded TLS connections
and checking that the bytes sent by the Go code haven't changed.

Previously we used GnuTLS's debug output and extracted the bytes of
the TLS connection using a Python script. That wasn't great, and I
think GnuTLS removed that level of debugging in a more current
release.

This change records the connection with Go code and adds a test for
ECDHE-AES clients generating using this method.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/5988048
crypto/rsa: fix Verify for multi-prime keys.

The least common multiple is not totient/gcd.

R=remyoudompheng
CC=golang-dev
http://codereview.appspot.com/5990045
html, exp/html: escape ' and " as &#39; and &#34;, since IE8 and
below do not support &apos;.

This makes package html consistent with package text/template's
HTMLEscape function.

Fixes issue 3489.

R=rsc, mikesamuel, dsymonds
CC=golang-dev
http://codereview.appspot.com/5992071
misc/dashboard: cope with removed Package fields.

adg removed some now-unwanted fields in Package a while ago,
but there are still datastore entities with those fields,
so we must explicitly check for ErrFieldMismatch and ignore it.

R=golang-dev, rsc
CC=adg, golang-dev
http://codereview.appspot.com/6007043