fixed mission info for Right 2 Live (again..)

added missing mission info for R2L

- Added missing models
- Added burned witch variant to map 5 (should have always been there)
- Added glow effect to howitzer in map 6

lots of stuff

(general)
* added unique mutation
* added secondary version of map 4 (for survival & mutation)
* updated precache function in all base scripts
* increased voice line volume

(map 1)
- stopped tanks from spawning after elevator
(map 2)
- removed invalid ragdolls
(map 3)
- removed invalid ragdolls
(map 4)
- added alternate path
(map 5)
- updated fog color
- added cover to helicopter fight
- added ranged glow to guards
- added bile bombs to ravine run (required spawns)
- last script now triggers before the 2nd tank (giving it reduced health)
-- updated tank health during escape (normal: from 1600 to 1200)
- added 'expert assistance'
(spawns extra items, removes 1 soldier from helicopter fight)


(mutation info)
Objective: Survive Dr. Malroy's onslaught
Name: Too Many Crushers (console: toomanycrushers)
Behaviors:
- Crusher health is very low
- Survivors revive and heal faster
- Survivors crawl when incapped
- Pipe bombs have 1 second fuse
- Bile bombs are converted to pipe bombs

Added sound ents from the Lab campaign to maps 1-4

(hot fix)
- added missing computer monitor model in map 3
- fixed bug with fireaxe spawn in map 1

fixed incorrect witch reference in map 4, added missing texture

added precache call to all map_coop scripts, fixed missing texture on scissors world model

added missing barrel model in map 4

added link