Changed main functionality.

Added arguments to main method.
Added ApplicationSystem class. All core features are used in this class.
Changed the number of threads used by the global threadpool.
Changed MainWindow constructor.
Changed Updater class functionality. Now only updates programs and
modules, but not itself.
Changed util file methods. Fixed some errors and added some
functionalities.
Deleted generateUUID method. Now, the UUID is a main argument.
Documented all completed code.