Minor cleanup of doxygen files
Updated Doxygen instructions
Spine updates

- File cleanup, renaming for consistency
- Added ability for Skeleton to use blending, flipping
Merge pull request #148 from lilligreen/development

File cleanup: Doxygen, Starter Project, Spine
Fixed some compiler warnings in Xcode
Merge pull request #150 from lilligreen/development

Fixed some compiler warnings in Xcode