Added default data for level packs in application bundle.

1. Corrected importLevels unit test in SaltrTests class.
2. Updated doxygen.config file.
Corrected unit test for loadLevelContentData function.

1. Removed Helper class.
2. Renamed Config header file to SLTConfig.
Merge branch 'master' of https://github.com/plexonic/saltr-ios-sdk

Conflicts:
	Saltr.xcodeproj/project.pbxproj