New game mode: Freezetag

[din0]

Classic freezetag mode

I liked Q3's implementation of the encasing ice when frozen, but would like it if the ice either melted or exploded without gibbing.

Static settings:

stand next to friendly frozen player (X amount of units away) for 3 seconds to thaw, thawed player respawns immediately

Tie into weapon banning/allowing to be able to have a unlimited railgun-only 1-hit freeze for instafreeze mode

Include lithium grapple