[Lua] Spy

-=Work in progress=-

Spy from Team Fortress 2. Work still in progress, so you can only disguise now. Press F to disguise, shoot to remove it. After removing, the ability has 3 seconds cooldown.

-=List of further updates=-
- invisibility
- fair and balanced random crits
- different weapons

Huge 1.1 update!
- now at melee range spy uses his knife
- you can kill an enemy with single stab if you attack if from behind!

!NEW!
1.2 update!
- testing a new weapon - Your Eternal Reward! This knife allows you to use your disguise only once after respawn, but after successful backstab you get the immediate disguise.

There are many glitches now that will be fixed soon. Tell me if you like the idea and if you want me to make other classes of TF2 (or maybe other games?) Suggest your ideas!