* 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]
for getting the list of variable names and for clearing all rule and
variable storage.
* compile.c - better error reporting for unknown rules; now it is a
hard error.
* hash.c/h - added hash_free to allow removal of elements from a hash
* rule.c/h - implemented rule freeing; stopped exporting rules to the
global module by default.
* variable.c - reclaim variable storage when disposing of variable
hash.
* build.jam - make grammar building work under NT
[SVN r18405]
