Redo code for forcing SP to FFA in multiplayer
Add sv_dorestart to tell map_restart to do a full map load

Set sv_dorestart in game VM if g_gametype is changed, so g_gametype is less special in engine.

sv_dorestart is based on code in Open Arena.
Make game VM use flags for tracking cvar, team shader, and doing full restart

Moved modificationCount to end of structure, so don't have to initialize it to 0 in the cvar table.