Upgrade SDL2 to final 2.0.0 version. Also remove so files to save space

Removed:
-Xcode*
-test
-VisualC
-acinclude
-android-project

Change-Id: I8eed893a005918291e00101f50c9301571a95dbc
Signed-off-by: Marc-Andre Laperle <malaperle@gmail.com>
Add DS_Store to gitignore
Update Windows build for SDL2.
Merge pull request #19 from MarkZ3/SDL-upgrade

SDL upgrade