-fomit-frame-pointer is included for any optimisation level above O2 (including Os)
Setting MACOS_DEPLOYMENT_TARGET is unecessary if you are just setting it the same as the OS X you are running.
This means our include directory is prioritised above all -I but after all other system directories. This is how it should be.
Also helps fixHomebrew/homebrew#113.
The classes better reflect their contents. I'm sure this change may be
contentious, but I am a sucker for trying to create source bases that are easy
to get to grips with and easy to navigate.
brewkit.rb is now a deprecated file.