Added obj/ to .gitignore
Marshaling refinements
Added SDL_messagebox wrapper
Merge remote-tracking branch 'origin/master'
Marshaling refinements to supplementary libraries
Change messagebox enum base types to uint

Change access level on messagebox internals to private
Merge pull request #25 from jameson-ernst/master

Marshaling refinements and SDL_ShowMessageBox
Merge branch 'master' into flibitRumble