[MP] Increase max number of scheduled EFX to 2048

The max number of scheduled EFX prior to this commit was 500, but some
maps were hitting this limit (such as atlantica). Increasing to 2048
should be enough for any map...

Conflicts:
	codemp/client/FxScheduler.h
[MP] Init dists and sides in R_ChopPolyBehindPlane.

Conflicts:
	codemp/rd-vanilla/tr_marks.cpp