Improve toolset versions support.

* new/toolset.jam
    (normalize-condition): New rule
    (flags): Call 'normalize-condition'

* new/gcc.jam
    (init): Set compiler name for all actions in
    gcc module, now that toolset.jam supports it.


[SVN r16906]

tools/build

@@ -1 +1 @@
-Subproject commit 4b4562f5d1ce3045ce160ad4a024f5b679bd8b43
+Subproject commit 5fc775a012931af7d973cb15ef60e58c41fa759f