Fixed a OCScript runtime error for the lightning strike
Make COMD_* work more intuitive for DFA_FLOAT

Changing from COMD_UpRight to COMD_Up now makes you go upwards instead of continuing in the diagonal direction.
This does not seem to break anything, although the C4Command.cpp code is hard to verify due to lacking comments. If this is broken I will fix it. In any case no one is using it anyways.
Clean up airship script and use float procedure to move the ship

This removes some functionality which I will implement later, but provides a better basis to build upon.