Added missions file in part 2 vpk

Stringtable Dictionary

[l4d2_ic06_rooftop]
- Unreachable items relocated

[l4d2_ic04_mall]
- Changes with fences during mall crescendo event.
- Added medkits seperated on two locations.
- Changed the crescendo event script to decrease density of common infected.
- Placed a trigger to stop the crescendo event script before you reach the button.
- Changed the tank into a witch after the crescendo event.
- Fixed a small navigational issue where bots would get stuck in the mall.

[l4d2_ic05_skyscraper] Fixed some doors which aren't meant to interact with, by locking them and setting them unbreakable.

Updated model error

An update has been released for Inferno City

[l4d2_ic04_mall]
- The crescendo event has been divided into two directions, randomized, making it a shorter path.
- The tank has a 50% chance of spawning now, also his location is on the end side of the hallway.
- There are a few items added before the mall event.
- Navigation outside the mall at ammo pile has been fixed.