[MP] Don't consider demo playback as connected to server state for cvar code.
[MP] Don't allow userinfo cmd to be empty.
[MP] Suppress "WARNING: CM_GridPlane unresolvable" message.
Added cm_extraVerbose cvar to enable it for development.  Does not save to config, must be explicitly set before map load.
[MP] in_disablemacosxmouseaccel was unused, removing.
[SP] in_disablemacosxmouseaccel was unused, removing.