This also eliminates the last pieces using that global string list. All relevant text is now in the external string table.
There's still too many loops but this at least gets rid of the empty ones.
- Input velocity now consistent irrespective of frame rate. - Angle and horizon calculated at frame rate. - Replace usage of F16() macro with fix16_from_int() in GetInterruptKeys(). Note: Known issues with look up/down keys that is to be repaired.