Adding faction change for Medivh

Medivh has it extremely hard when it comes to recruiting, I think some of that is caused by "poor" infrastructure taken the amount of players in to consideration. Adding faction change could change the recruiting game a bit. I guess it would be easier for horde players who find themselves unsettled to just faction change than it would be to do the "hard" reroll and go to alliance side, and vice versa.

It already has dual specialization, so wanting to be "a non custom server" is not a viable excuse to not implement it. :)