Need reviewer: minor makefile fixes

[Kelly O'Hair]

Need reviewer: minor makefile fixes

6932743: Makefiles not parsing version strings with - from uname -r
   On some Linux systems the "-" character in uname -r has caused some  
makefile version number extraction problems.
   This just allows for the "-" character as a separator.

6974005: Use of cygpath in Makefile logic needs to silence error  
messages
   On Windows, error messages from cygpath can get included in the  
path name or as the pathname.


http://cr.openjdk.java.net/~ohair/openjdk7/make-6932743%2b6974005/webrev/

-kto