Bugfix: Fixes mining borg's radio to the supply frequency since mining frequency no longer exists.

Feature: Introduces and adjusts code for cyborg and AI custom sprites

Cleanup: Streamlined the AI core selection code. Could probably be even cleaner but it's good for now.
blrg... didn't update my ai code before commiting, should be fixt
Merge pull request #3232 from Ravensdale/master

Custom synthetic sprites and minor bugfixes