Map dm_fenrir for cs 1.6

DM_FENRIR By Victor-933 for HL1DM NEW TEXTURES: YES NEW MODELS: NO NEW SOUNDS: YES NEW SPRITES: YES Credits: Textures: Heavily edited variants from multiple sources -- chiefly, Nightwatch (nw.wad), Poke646 (poke646.wad), and Shaderlabs Majestic Pack. A few were even made from scratch by me! Sounds: Edited versions lifted from Doom 3 and Black Mesa Source.