Callum recreates GMod's main menu in VGUI

In #developer-talk, Callum showed GMod's main menu fully recreated with VGUI. He said VGUI will always be a little slower but it's fine for a main menu: about 300 FPS on the DarkRP server list versus 500 with HTML. Akiko noted that one upside of the HTML menu is it immediately shows when the HTML backend is broken.