Mhm hmm...

(Apparently Kart made this exact fix 2 years ago and it was never backported?)

Fixes culling issues in CEZ2 skybox

This was causing a buffer underwrite too. Lovely.

This reverts merge request !1309

Fix dropshadows of papersprites drifting depending on angle relative to camera. Discovered in Kart internal for the paper item drops and ported back, hence the branch name.

This makes it print nothing to stdout.

Also fixed some irregularities.

This removes Makefile.depends. Instead, '.d' files are included from the 'dep'
directory. This speeds up building because dependencies for every file don't
need to be regenerated if only one changes.

As a bonus, dependencies also won't be generated if only clean type targets
are going to be run. Also added a 'distclean' target, which cleans both
objects and dependency files.

MOBJCONSISTANCY checks confined to gamestate GS_LEVEL. DEBUGMODE
no longer implicitly enables them, making it netgame-compatible.