Slimes

Added a slime scanner. Two are available in extract storage.
Fixed some targeting issues, notably them not chasing targets at all and re-picking target every tick.
Fixed a bug where friends list wasn't passed down after splitting.
NPC slimes can talk and have limited speech understanding. They can be given simple orders by friends.
Slime smiles ![slimesmile](https://cloud.githubusercontent.com/assets/6681708/2851821/fdca231c-d123-11e3-9299-16f0273db19d.png) - this is his 'gonna eat you' face.
Mutation chance is not fixed 30% now, it varies between 25% and 35% for every slime. Use scanner to find it.
Slimes will now stop chasing target when sprayed with water.
Slime extracts now use 1 unit of reagent instead of 5.
Slimes will hunger much slower, but use nutrition to grow. It's still about the same amount of food they need to evolve/split, but handling multiple slimes is less frustrating. 
And various code cleanups.