SRB2 release v2.2.13

Disable renderhitbox in multiplayer altogether

See merge request STJr/SRB2!2142

Fix floorsprite rendering with 1x1 images

Closes #1052

See merge request STJr/SRB2!2141

Replace CV_NETVAR with CV_NOTINNET for cv_renderhitbox (Fixes #1103)

Closes #1103

See merge request STJr/SRB2!2140

Expose skin.supername to Lua

See merge request STJr/SRB2!2138

Optimize sprite rendering by ignoring completely occluded sprites

See merge request STJr/SRB2!2131

Interpolate Hitboxes when Scaling Mobjs

See merge request STJr/SRB2!2124

The CV_NETVAR flag being used for cvars not registered in a dedicated server context will completely mess with the internal netid to cvar linkage.
And I'm not really keen on registering a cvar purely for rendering on dedicated servers, so let's just prevent renderhitbox from being changed in netgames entirely.

Make camera noclip during NiGHTS gameplay

See merge request STJr/SRB2!2136

Fix possible crashes in the Lua API when accessing invalid fields

See merge request STJr/SRB2!2128

Allow input during title animation after the first time

See merge request STJr/SRB2!2122

Don't Copy mobj->dontdrawforviewmobj To MT_OVERLAYs

See merge request STJr/SRB2!2125

Don't attract bomb spheres with Nightopian Helper

See merge request STJr/SRB2!2135

Fix the Record Attack Background Jumping

See merge request STJr/SRB2!2129

Add toggle for instant retry in Record Attack

See merge request STJr/SRB2!2120

Make renderhitbox a netvar to prevent clientside wallhacking

See merge request STJr/SRB2!2133

Fix sprite scale column iteration crash

See merge request STJr/SRB2!2130

This has the effect of misrepresenting how many sprites are actually visible, but it's more "accurate".