Variety of performance improvements.

* 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]

src/engine/parse.c

@@ -17,6 +17,7 @@
 # include "newstr.h"
 # include "modules.h"
 # include "frames.h"
+# include "debug.h"
 
 /*
  * parse.c - make and destroy parse trees as driven by the parser
@@ -78,6 +79,8 @@ parse_make(
 	int	num )
 {
 	PARSE	*p = (PARSE *)malloc( sizeof( PARSE ) );
+    if ( DEBUG_PROFILE )
+        profile_memory( sizeof( PARSE ) );
 
 	p->func = func;
 	p->left = left;