Prevent warnings about incompatible builds... we know they are as we try and build everything.

[SVN r21360]

Jamfile

@@ -121,6 +121,8 @@ local lib-sources = [ install-sources lib ] ;
 
 if $(lib-sources)
 {
+    local gNOWARN_INCOMPATIBLE_BUILDS = TRUE ;
+    
     local lib-build =
         debug release
         [ cond $(with-debug-python) : debug-python ]