Refactored the way URTrator working with profiles - now everything
that could be taken from internal cache will be taken from cache.
The very same as with servers.
Moved all callbacks from callbacks to events, so we achieve full
asynchronity here and can launch anything in goroutines :).
Moved MainWindow-related game launching functions into another
file (mainwindow_launch.go).
Made quick connect widget working. Note, that even if you're on
Favorites and trying to connect to one of favorited servers but
with quick connect - you still have to choose right profile
near Launch button!
Maybe something else I forget.
Added checking if Urban Terror launched while trying to shut down
URTrator. If yes - we will show error message and won't quit,
until Urban Terror will be dead.
