STLplus 2.5 released

Fixes to compatibility problems and some tidying up:

- Fixed compatibility bug so STLplus compiles with gcc v4
- fixed bug in file_system definition of read_mode
- updated documentation for iterators to match the code
- rationalised the use of typename to support Visual Studio 6, 7 and 8
- Rationalised macros for Microsoft Windows build
- Removed debug trace code now that the code is considered pretty stable

Note: please use existing makefile package - this has not changed

See http://stlplus.sourceforge.net/stlplus/docs/changes.html