bug fix: added -L/usr/X11/lib -lpng12 flags for Mac OS X
bug fix: added -L/usr/X11/lib -lpng12 flags for Mac OS X

git-svn-id: 38c604b3104e32f2a99bb63601c3e294170c19ce@1003 425b54fa-293c-0410-bdda-a7e424c12f17

IceDragon200/starruby,hajimehoshi/starruby,hajimehoshi/starruby,IceDragon200/starruby,IceDragon200/starruby,IceDragon200/starruby