UFO:Alien Invasion Code

* Removed unnecessary glcmds from the md2 models

* rotated geoscape models

* removed glcmds from md2 files (to reduce the filesize)

*fixed rotation
* rescaled

* rescaled and fixed texture path

* new ufo corrupter geoscape model by sitters

* reexported

* fixed segfault when using CP_ChooseMap() without pos given in parameter
* added corrupter in code (can be used for harvest and terror mission when XVI spreading started)
* skip XVI spreading caused by mission if XVI spread did not start yet
* ufo_condor.{md2|tga} => ufo_corrupter.{md2|tga}
* note: corrupter can't appear on geoscape yet, because maps.ufo shows no map with corrupter, and because corrupter model has more than 4096 verts.

* use the trunk base content

* delete the base to allow to copy the trunk one