Cmake refactorings and fixes

This should fix building cocos2d-x on Mac, next I plan Windows, and then big refactoring to state when other cmake projects and applications can find cocos2d libs from their CMakeLists.txt files.
I do it because it seems that work on cmake framework somewhere stalled [forum](http://discuss.cocos2d-x.org/t/cmake-for-mac-qtcreator-and-clion/16889/57).

This patch includes these changes:
* Fix build tests for Mac (for this connect to build into cocos2d some missing parts: UIEditBox, protobuf, audio)
* Convert test applications for Mac to bundles to easy start and properly find Resources folders
* Move `cmake/BuildHelpers.CMakeLists.txt` to `cmake/Modules/CocosBuildHelpers.cmake` so it can be easy included from another projects in future.

I test build and samples on Mac (with ninja and Xcode generators) and Linux (with make generator). Next I plan to fix Windows MSVC generated projects.