Merged Boost.Locale to release branch
Merged chagneset 74174 from trunk
Merged changeset 75174 from trunk (clang issue)
Merged changesets 75594,75601 from trunk, incorrect used of 
MultiByteToWide in detection of invalid sequences.
Lineup with trunk
Lineup with Boost.Trunk

Fixes:

- Fixed compilation with requirement of boost_system
- Fixed some problems with STLPort builds
Lineup with trunk