Replaced all uses of $(DIST)/include with $(PUBLIC) except those looking for NSPR headers.
Removed extra instances of $(DIST)/include or $(PUBLIC) from INCLUDES as it's already there.
Override OS_LIBS when setting host variables for cross-compiling.
git-svn-id: svn://10.0.0.236/trunk@57356 18797224-902f-48f8-a5cc-f745e15eee43
