remove gcc flag -Wnewline-eof on Mac

this is an unstandard flag, causing us problems on newer versions of Apple's GCC
(4.2 was fine, 4.7 was causing errors)

see https://github.com/joyent/node/pull/3887
and ML discussion titled "[nupic-dev] Building in OS X 10.6.8"
Merge pull request #167 from breznak/apple-gcc-fixups

remove gcc flag -Wnewline-eof on Mac