Avoids armv64 to compile with xcode 5.1.
Updates logic submodule. Refs #45.
Uses n_global.nim from logic submodule. Refs #45.
Updates build script clean targets' paths. Refs #45.
Moves more objc to logic submodule. Refs #45.
Uses new NSStringFromClass wrapper. Refs #45.
Documents task in changes log. Refs #45.
Merge branch 'feature/t45_refactor_common_code'