-added the Riftkeeper Mk II, a stronger variant of the riftkeeper for the lates stages of the game
-added Riftkeepers to the final mission (you can add more or remove them in the XComRiftkeeper.ini)
-minor AI improvements
- Those of you who use custom inis: I made the code a bit more efficient, but the ini structure changed slightly. So dont just use your old ini with the new mod version.

-tweaked the Riftkeeper AI a bit (should be a bit more challenging!)
-toned RiftBeacon cost down a notch, especially for lower difficulties
-added ini values for several settings, including riftbeacon costs and spawnarea
-since the riftbeacon technology is new and dangerous, soldiers using it now suffer a small wound
-fixed some minor bugs