Custom Map: Crossfire

Adds Half-Life's Crossfire deathmatch map. The map was remade from scratch using Hammer Editor as reference and imported into the game. It's not a 100% match to the original map, but I'm pretty sure it's close enough. Besides, I have added a few new additions.
MapLoader is required, otherwise nothing happens.

Credits to Bippuit for helping me by importing the map into the game.