Beginning migration to CMake, builds work on mingw & msvc

Now need to test builds on Linux and OS X vm's
Everything worked on Linux & OS X 10.8 so moving ahead
Fixing finding of SDL2main library and now properly linking SDL
Adding FindSDL2_image and now building Lesson3
Fix case
Migrating Lesson 4 & 5
Building lesson 6 and cleaning out 7 & 8
Add bin directory to ignore
CMake seems to randomly choose between 32/64bit libs on windows

To solve this I'm removing the 64bit directories from the search paths
to force it to only find the 32 bit directories on Windows. Added a note
so other folks who want 64bit know how to add it back in
Fixing readme formatting
Setting that flag for msvc isn't necessary i think
Testing out improving handling of 64bit builds

Detect if 32 or 64bit build and look up the correct libraries
Improving handling of library dependencies

This way we don't look for the extension libraries unless we need them
for the project we're building.
Look up correct lib paths for msvc
Working on adding proper error handling.

Will show the full error handling in lesson 1 then introduce the cleanup
convenience function prior to lesson 2
Merge branch 'cmake_migration'