fix uninstalling research/country/region mods
move some terrain-specific data out of deployments

and allow definition of civilian units per terrain while we're at it

(this is a tftd requirement)

also get rid of that hackish rng in the deployment getTerrain() function
fix OSX issue
don't center on melee attacks by aliens against civilians
fix -1 situation
More size_t
- Fixed some text lists crashing the game (eg. ufopedia armor).
- Improved music playback.
account for screen offset when finding button idx
Merge pull request #808 from myk002/fix_psi_button_calculation

account for screen offset when finding button idx