Reduce consing for find-package.

Don't use return-from inside restart-case, it causes consing even when
the branch with restart-case is not taken.
Optimize pprinting of heavily nested lists.

Declare types of PREFIX and SUFFIX slots of PRETTY-STREAM to be
(simple-array character (*)), not just simple-string.
make-array transform error on unknown element-type.

Check for the type to be known, otherwise give up transforming.
Based on a patch by James Kalenius.
Fixes lp#1156095.
faster SVREF and (SETF SVREF) compilation
micro-optimize sane-package a tiny bit more
Fix SEQUENCE:SEARCH, test seq. functions with user-defined sequences

Extending the tests in tests/seq.impure.lisp to user-defined sequences
revealed that the previous implementation produced incorrect results
for some inputs.

SEQUENCE:WITH-SEQUENCE-ITERATOR now accepts NIL in the list of
variables and generates ignored bindings for these elements.

The new implementation is also slightly faster (at least for the
inputs in tests/seq.impure.lisp).

fixes lp#1153312
minor NEWS fixups
Fix typo in comment in src/compiler/seqtran.lisp
Remove redundant LENGTH calls in NSUBSTITUTE[-IF[-NOT]]

NSUBSTITUTE, NSUBSTITUTE-IF and NSUBSTITUTE-IF used to contain

  (let ((length (length sequence))) ...

in the code path for lists. In the macroexpansion it became clear that
this recomputed and shadowed the LENGTH variables already established
by DEFINE-SEQUENCE-TRAVERSER.

A very brief test with list lengths between 5 and 500 suggests that
the speedup produced by removing the redundant computation can be
around 5 to 20 %.
Lazy length computation in DEFINE-SEQUENCE-TRAVERSER

DEFINE-SEQUENCE-TRAVERSER used to unconditionally establish a binding
of LENGTH{,1,2} to the length of the processed sequence(s). This was
wasteful in the case of user-defined sequences whos implementations
could not access this information.

DEFINE-SEQUENCE-TRAVERSER now uses SYMBOL-MACROLET to provide LENGTH{,1,2}
symbols which evaluate to the respective sequence lengths, but the
sequence length is only computed when needed.

Uses of DEFINE-SEQUENCE-TRAVERSER now have to avoid forcing
LENGTH{,1,2} and thus END{,1,2} handling only appears in the list- and
vector-code-paths. The affected sequence functions are REDUCE,
DELETE[-IF[-NOT]], REMOVE[-IF[-NOT]], REMOVE-DUPLICATES,
DELETE-DUPLICATES, SUBSTITUTE[-IF[-NOT]], NSUBSTITUE[-IF[-NOT]],
COUNT[-IF[-NOT]], MISMATCH and SEARCH.
Declare types of END and TEST in N{LIST,VECTOR}-SUBSTITUTE-IF[-NOT]*

The types of END and TEST are known because the respective callers are
defined with DEFINE-SEQUENCE-TRAVERSER which checks/COERCEs
appropriately.
test environment fix for 64-bit PowerPC/Linux

(from Eric Marsden sbcl-devel 2012-03-26)
1.1.6: will be tagged as "sbcl-1.1.6"
remove sb-studio from commercial support section of the manual

(thanks to Titus Barik)
Fix a compilation failure on svref of a symbol macro

 Introduced in 0892423b (faster SVREF and (SETF SVREF) compilation)

 Thanks to James M. Lawrence for the quick report, with a reduced
 test case.
Stop emitting references to inexistant #n= forms in the pretty printer

 * Special logic was introduced in 2003 to avoid pprinting backquote-comma
   forms as ", foo" when ",foo" is unambiguous; the bug has likely been
   around since then.

 * Reported by Douglas Katzman on launchpad, and reduced by James M. Lawrence
   (lp#1161218)
type=: Compare &key parameters of function types.

Compare key parameters in type=-args, mostly so that deftransforms
with key arguments could be redefined at runtime.
Check bounds of ELT on &more in safe code.

Disable &more optimizations for ELT if safety = 3.
Don't signal an error on (setf (documentation nil 'function) "doc").

Signal a style-warning instead when trying to set documentation of NIL
for all other documentation types (except TYPE).

Reported by Zach Beane. Regression since 2e52fa05.
LOGBITP and LOGTEST optimizations from x86.

Copy Nathan Froyd's optimizations for LOGBITP and LOGTEST
on x86 architecture into x86-64.

Committing change submitted by Doug Katzman.