Windows Building Improvements

Building on Windows should now be much easier:

• SDL (all parts) is bundled in the git repo in binary form, so you don't need to get that or set it up. These are the latest versions of SDL, which include some useful bugfixes.
• Likewise the latest zlib is bundled in binary form.
  
• Boost.Python is bundled in source code form, and compiles correctly, which prevents the need to get or set up Boost at all. This is very nice as the precompiled Boost we previously used assumed you were using Python 2.5. Consequently, the engine will now build using Python 2.6.

The process should now be very easy, basically just

• Get git, scons, CMake and Python.
• Get the Intensity Engine source code.
• Build V8.
• Run CMake to generate a VC++ project file.
• Build the project in VC++.
  

For specific details, as usual see the COMPILE.txt file.

I develop on Linux, so sometimes the Windows stuff gets delayed, sorry about that. Speaking of which, volunteers willing to help with Windows and OS X stuff would be very welcome.