remove unimplemented ban action from user context menu

fix some indentation

fix view limits in stereo 3d

fix for issue #234 - the framebuffers for side-by-side and top/bottom had alpha channels. so when sprites with alpha were blended into the framebuffer it would blend the sprite pixel alpha with the fb pixel alpha

display airplane altitude indicator also with drill strike and air attack - when more-wind is activated

crate hat. partly based on Hadashi's draft