NEW COOP BASED:
* Add "Infinite" option to cv_cooplives, inspired by SUBARASHII. Lives still exist, but are hidden from the player's view, and are prevented from falling below 1 at any cost. As a result, made the variable CV_CHEAT.

OTHER MULTIPLAYER BASED (semi-related):
* Made cv_autobalance an on/off switch which determines the allowed difference based on the number of people in the server, instead of a weird and opaque number from 0-4.

MENU BASED (not related):
* Add horizontal arrows to menu options which respond to the arrow keys.
* Make the menu arrows bob.
* Switch out the seperate arrows for combination arrows on the joystick menus.
* Minor cvar description tweaks.