Further fixing of JIP component

Should now work reliably with JIPing and respawning players.

* added new file in f\JIP: f_JIP_setup, governs optional features of JIP component and allows for small delay in adding the respawn eventhandler (lack of delay was causing the issues)
* f_fnc_assignGear now sets a public var per unit ("f_var_assignGear")
* changed eventhandler added by F3 to "MPrespawn"
* new options for JIP component:
  - remove old player corpse
  - disable JIP gear menu (will give player old gear assigned by f_fnc_assignGear and set as "f_var_assignGear"
* Tweaked group menu slightly to allow players to stay in their existing group (if it has > 1 unit still present).

Note: This PR is mostly for the technical side of things. Naming of files, variables, comments etc can still be changed/tweaked if so desired.