Reorder map loading

See merge request !635

Extra functionality for lua

See merge request !601

Remove "z" from "vertex_t"

See merge request !636

Provide a fix for "non-sloped" slopes launch/land behavior by checking the normal's components.

See merge request !634

Adapt P_ClosestPointOnLine3D() to be much like FV3_ClosestPointOnLine() and use vector3_t's as args, save for the hypotenuse calculation, which remains the same; the output should be the same as before.
Adapt the rope hang snapping to the new function's form.

Move P_ProcessLinedefsAfterSidedefs into P_LoadMapData, but move map data copying after everything else

Compressing sidedefs can break both special effects and netgame syncing, so let's get rid of it

See merge request !628

Textmap parser

See merge request !604

Fix major issue

See merge request !625

Remove Direct Draw from AppVeyor config

See merge request !622

CV_FindVar for Lua

See merge request !583

Do not save netgame-synced console variables

See merge request !623

Let the mouse move freely when a menu is open or game is paused

See merge request !617

This is a bad thing to do, because if you join a server,
your game will save the host's settings.

This reverts commit 17636ccc.

Allow 6-letter character names to be drawn with the thick font

See merge request !618

Fix MP Special Stages crashing if a player is being carried when it ends

See merge request STJr/SRB2!615

Add slots for unused sounds and remove unused sound slots

See merge request !603