Cleanup done while researching the Boost Jam internals. Added better implementation description comments at many places. Cleaned up the 'dependant' and 'dependency' terminology that got mixed up in several places. Renamed several functions to use underscores as word separators.
[SVN r48480]
* bjam; bump to version 3.1.12
* bjam; make it possible to build in MinGW/MSYS shell
* bjam; move profile code to debug.h/c to make it available for use everywhere
* bjam; cache all filesystem query operations, Unix and Windows only, include PWD and scanning
* bjam; add memory profile info, and sprinkle throught code
* bbv2; rewrite some while() loops into for() loops to reduce time and memory
* bbv2; keep a single instance counter instead of one per type to reduce memory use
* bjam+bbv2; change NORMALIZE_PATH builtin to join path parts to reduce memory use
[SVN r31177]