Fix for control sensitivity issues related to switching between MP and CM/SP

[tobiasksu]

Reminder to self to check in code related to this very old issue reported by Miasmic and others. Have code laying around that I've had Miasmic test, refresh self on topic to see if solution still OK. Related to handling of frametime/fps timers in GameManager.Update().

[roncli]

@tobiasksu Maybe you can poke @CCraigen into bringing this one to light as well. :)