Comprehensive Setup Instructions for Mac OS X & Windows

This is my first pull request, so bear with me...

I corrected some errors that prevented the Mac OS X instructions from working on all setups. Namely, I corrected it to instruct to modify the .bash_profile instead of .bashrc. This is because the login terminal doesn't check .bashrc. I also chose .bash_profile over other acceptable alternatives because some programs, such as MacPorts, creates the .bash_profile file. This file will supersede all other bash profiles (and even prevent them from being read).

I also reformatted both the Mac OS X and Windows instructions to provide a linear flow detailing the setup process from start to finish. During this process, I copied and adapted some instructions from the Mac section that were previously missing from the Windows section. It is counterintuitive that a Windows user should read the Mac section for the full installation procedure.

To streamline and prevent any problems and headaches during the setup process, I have also created a new Preliminary Instructions section detailing the minimal requirements to complete the installation and warning users to wait on connecting their Ouya to their computer until after setting up the USB.