Adds Synthmeat, Synthbutt, and Synthbrains to Botany, along with some other stuff

![14h67p5](https://cloud.githubusercontent.com/assets/4081722/3295562/eba83236-f5c3-11e3-9cde-6cf4642f34e5.png)
Thanks to the goons for permission to use the sprites.

Adds Synthmeat, Synthbutt, and Synthbrains to Botany.

Removes meat from the biogen because you can grow it now.

Re-checks the buttbot and makes it compile. I don't know why it wasn't checked in the first place. If it was they would of noticed the compile issue.

Fixes being unable to make cash seeds from cash trees.

I tested buttbot.dm and it works as intended.