Fix HeldJump timer

Fix case where timer would still be active if the the enabled cvar was
turned off after the timer was created.  Creating a case where a player
was stuck with their jetpack on.
Change Jetpack Bling donator menu title

Changed for clarity
Give client a default jetpack

Handle case where a client who did not have a cached jetpack cookie
would recieve whatever the previous client index had as their jetpack
Merge pull request #1 from CrimsonTautology/fix-holdjump

Fix issues