Fix conc speed being limited for too long after using a jump pad
 * Fixes #80
 * Will stop limiting once the player is on the ground or in water, or after 3 seconds has passed since the jump pad was used
 * Also made the jump pad set players as in the air, so that m_flMancannonTime doesn't have to be checked in CFFGameMovement::CheckJumpButton (being in the air will force an early return)
Merge pull request #81 from fortressforever/fixes/jumppad-conc-limiting

Fix conc speed being limited for too long after using a jump pad