Initial commit of v4 of boost.regex on regex-4 branch

svn path=; revision=18128
Removed auto-selection of no-recursive implementation - it's not ready yet!

svn path=; revision=18132
Fixed nasty typo

svn path=; revision=18133
Added performance test files

svn path=; revision=18134
Added non-recursive algorithms for single character repeats

svn path=; revision=18170
more or less completed non-recursive implementation.

svn path=; revision=18185
finishing off non-recursive memory management

svn path=; revision=18186
Finally fixed non-recursive algorithm - should now be fully usable, and is now emabled by default on non-win32 platforms.
Fixed a couple of buglets in the regex comparison benchmarks.

svn path=; revision=18191
Added test cases for independent sub-expressions

svn path=; revision=18204
Added support for independent subs
Almost complete implementation now

svn path=; revision=18205
Fixed buglet in independent subs
Added more independent sub test cases

svn path=; revision=18207
Added new docs,
Moved source more into line with the std lib proposal.

svn path=; revision=18292
Recovering from cvs repository crash: readded regex iterator code.

svn path=; revision=18360
Added regex iterator examples and docs, recovering from cvs repository crash...

svn path=; revision=18361
Final tweaks prior to release...

svn path=; revision=18399
Final tweaks, almost ready for release...

svn path=; revision=18400
Finished checking docs, code should now be ready for release...

svn path=; revision=18428
Removed old branches.

svn path=; revision=38550