Improve mega selection in randoms

Megas now have their own viable moves, so that more unique megas like Heracross, Charizard and Mewtwo can have their viable options.  Someone who knows pokemon more should edit the other megas so that their moves are viable - for now I just copied the same moves their original form has, with a few exceptions.

Potential mega evolving candidates can now be selected without their mega stone.  For example, if the team has Gengar with Gengarite, Heracross without Heracronite can be added.
This block would become redundant.
(Though we might want to preserve the Mawile specific line. Just move it to the same section where Combee is assigned Honey Gather).