Moved previously builtin modules 'GameCenter', 'AppStore', 'iCloud' to separate modules to be represented as plugin.
Modified 'ARKit' and 'Camera' to not be builtin into engine and work as plugin.
Changed platform code so it's not affected by the move.
Modified Xcode project file to remove parameters that doesn't make any effect.
Added basic '.gdip' plugin config file.
Sergey Minakov