Add initial Linux support

This pull request includes the following changes:

* Addition of a 'Make' compiler folder, for use on Linux-like machines (BSD support has not been tested yet!)
 * Makefiles for Torque2D, zlib, lpng, ljpeg are all included.
* Rename 'box2d' folder to 'Box2D' to fix case sensitivity problems.
 * Includes changes to relevant project files for other platforms.
* Change a number of includes throughout the codebase to use proper case.
* Fix OpenAL searching and functionality for TORQUE_OS_LINUX
* Add necessary platform methods, some of which are currently stubs until SDL 2.0 is used.
* Fix platform main loop.
* Removed CD audio support since no other platforms support it anymore and it's basically irrelevant.
* Cleanup a few places with dead code.
* Get cpu frequency reporting to work correctly.