Continuing merge of CMake build system files into trunk with the encouragement of Doug Gregor
Updating CMake files to latest trunk. Added dependency information for regression tests and a few new macros for internal use.
Fix for building with /Zc:wchar_t-.
msvc warning suppression.
Fix gcc warnings from ICU wrappers.
Add optional support for marked sub-expression location information.
Add support for ${n} in format replacement text.
Fixes #2556.
Fixes #2269.
Fixes #2514.
Empty expressions, and empty alternatives are now
allowed when using the Perl regular expression syntax.  This change has
been added for Perl compatibility, when the new [syntax_option_type]
['no_empty_expressions] is set then the old behaviour is preserved and
empty expressions are prohibited.  This is issue
[@https://svn.boost.org/trac/boost/ticket/1081 #1081].

Fixes #1081.
Fix gcc warnings.
Fixes #2623.
Update version number
Fixes #2437.
Fixes #2713: change table initialisation so that it's initialised statically.
Workarounds to allow compilation by Sun studio without the -library=stlport4 option.
Add PDF generation options to fix external links to point to the web site.
Added a few more Boostbook based libs that were missed first time around.
Fixed PDF naming issues.
Patch for ICU on AIX.
Windows CE does not define the wcscoll function from the CRT so, for WinCE, don't try to pull wcscoll from the global namespace into the std namespace.
Allow ICU_PATH path-constant in project-config to work.
It is only affecting build if not ICU_PATH is set on command line.
Make the wording of messages consistent with other libraries.
Added possessive modifiers ++ *+ ?+ {}+.
Added support for \v and \h as character classes as per Perl-5.10.
Added support for \g \K and \R.
Add support for named sub-expressions.