Stop -Wuse-after-free warnings

See merge request STJr/SRB2!1805

Stop -Waddress warnings

See merge request STJr/SRB2!1804

Only set default skin/color when possible

See merge request !1772

Fix "unknown command" not being printed on dedicated

See merge request STJr/SRB2!1771

Fix map number checks when reading unlockable conditions

Closes #882

See merge request !1807

Add more menu graphics to the whitelist.

Closes #765

See merge request !1731

Fix size_t compiler warnings in P_WriteTextmap

See merge request !1785

Fix description of A_ParentTriesToSleep

See merge request !1784

Make autobrake account for scale

See merge request !1782

Fix semibright/fulldark frame flags not working with 3D models

See merge request !1779

Purge a bunch of legacy/unused stuff

See merge request !1801

Aren't used and definitely should not be in here anymore

Blast from the past, buuuut let's trim the fat here too.

Written in VB6. Superceded by better tools and also probably not even
buildable anymore.

SRB2 no longer works with 1.2 or Dreamcast so these are irrelevant

Superceded by far superior tools

Once more, SRB2 no longer works on DOS so this is irrelevant

SRB2 no longer works on DOS so this is irrelevant

Also unsupported and nonfunctional

This thing is ancient history and also depends on FMOD.

cmake: Various macOS build/package improvements

See merge request !1800

yay icon

This properly links dylibs set during build instead of expecting
the libraries to be in the system path.

UDMF conversion: Fix noclimb flag not being applied to linedef types 66-68

Closes #868

See merge request STJr/SRB2!1790

Fix copypaste error in P_GetMobjGravity

Closes #867

See merge request STJr/SRB2!1791