Release-7-params : Fix version - Return to UI after emulation exit

Version changes on request :

• [Fix] If the emulation is started from Mame4all UI, returns to the UI when emulation stops. If the emulation is started from a frontend, returns to the frontend when emulation stops.

Edit : Added a mame4all-params-7-skipwarnings_ui_only.opk for those who don't use any frontend and only need the original Mame4all UI. It limits the deployment to a single icon.