Changed OS X build script to use proper shebang and correct path for extract-commit-info.sh

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Minor edits of README

Make OSX instructions more clear and command-line instructions a little more robust.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Changed all the #buildScript for the different platforms.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Merge pull request #17 from smarr/fixes/osx-build

Minor fixes for the OS X build