fix shooting in debug mode
fix z-axis scrolling
fix explosion animation speed
fix pathfinding arrows under bigwalls
fix big unit rendering around bigwalls and such

look away, children, look away.
fix for bug 268
fix letterboxing with intro disabled.
fix shading
Text fixes.
Avoid rounding errors.
This too
Fixed cases where live aliens weren't sold when the option was enabled.
Fixed StatString bug