Updated portuguese translation.
remove hard-coded live alien checks for research projects.

making use of the fact that getUnit can now return 0.
Save humanity from total annihilation.

break the iteration instead of resetting the iterator, as a base cannot
contain the same research project twice.
fix grammatical error in variable name.
Revised gender-specific strings.
Added a threshold to compensate for city-check coordinate difference.
fix bug with multiple minimized interceptions vs terror ships

handling for null pointers on UFOs after they become terror sites.

the "aliens terrorize <x>" popup is enough, not setting the ufo to undetected
removes the "ufo lost" popup and causes craft to return to base on their own
without popping up a "redirect craft" window.
don't send skyrangers back to base.

Extending the previous commit a little, this adds handling for landing craft
sent to intercept a landing terror ship.