osx:
* Updated formal credits.rtf file to new years (but currently is unused)
* Added a custom About panel, which alternates between AUTHORS and COPYING
* Removed help menu item to COPYING.pdf and removed COPYING.pdf
* Updated formal Info.plist version
* Added long-due LLVM license notice.
osx: disabled Xcode "unused function" and "unused variable" warnings
osx: cleaned up frontend code
osx: updated hard-coded credits a bit.
Capability for interpolation of player viewpoint and mobj locations.
TODO: sector heights, a few bug fixes
MP2E's compiler doesn't have an overload of abs() for long long; use llabs instead.
* Add Odamex to "significant code" section w/special credit to dr_sean
* Alphabetize significant code and libraries/utilities lists
Fix Russell's name
Sector height interpolation
Interpolation for camera viewpoints.
Removed "low precision" span drawer engine.
Remove lptex64 hack in do_draw_plane
Minus one more option nobody needs.
Seems to fix ConSiGno's loss of interpolation after non-blocking screenwipes.
Remove debug display
Proper interaction of deep water with interpolation.
Missed a few instances of use of viewplayer->mo->subsector->sector
Option r_boomcolormaps applies the view.sector's colormap to all rendered sectors, for backward compatibility. Currently cvar only.
Minor cleanup
Changelog update: 12/25 to present.