UFO:Alien Invasion Code

* base/models *.png files crush.

* crushed png files

* Reduced filesize of the alien ion_condenser texture by removing redundant texture parts and compressing/optimizing the file with pngout afterwards

* recompress images with pngcrush, with gains varying from very small to 28.3%

* use the trunk base content

* delete the base to allow to copy the trunk one

* reverted huge parts of 7566 that were accidentally commited

* introduced one static popupText array (use this instead of several other static char arrays)
* fixed MN_Popup calls with none static char arrays
* extended error messages for save function

* Deleted some unchanges stuff after talk with mattn.

* Added Ion Condensor Model by ProtoArmor.