Fixed RGB Matrix editor "image" model UI consistency

Fixed Function Wizard buttons with icons
Added fixture: Pro-Lights LumiPar 18 Tri (thanks to Lorenzo Andreani)

Added fixture: American DJ Mega Tri Par
Function wizard: buttons are now grouped into a solo frame

- partially checked items are to be included
NEW: Added Audio fade in/out support (also in Show Manager)
Removed noisy debug message