Fix usage of V_GetColor

See merge request STJr/SRB2!638

Use GCC 8.1 for AppVeyor 64-bit builds

See merge request !624

Add clipboard functionality to the Connect via IP textbox.

See merge request STJr/SRB2!597

I was using V_GetColor in a lot of places I shouldn't have, making the game look wrong with a non-default colour profile.
Though, I left R_RainbowColormap alone.

Fix major issue

See merge request STJr/SRB2!625

Remove Direct Draw from AppVeyor config

See merge request STJr/SRB2!622

Do not save netgame-synced console variables

See merge request STJr/SRB2!623

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

See merge request STJr/SRB2!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.

NOHW V.S. Renderer Switching

See merge request !609

Stuff I Broke: Commands

See merge request STJr/SRB2!607

Properly fix the issue that !528 tried to; let the -warp parameter work with map name

See merge request STJr/SRB2!596

That means you can now easily move your mouse out of SRB2's window
and switch between several windows easily by just pressing escape!

Any phase of the game that isn't actual gameplay counts as a menu,
which means you can also move the mouse in cutscenes,
at the title screen, server connection screen,
and even when the chat or console are open.

Revert "Merge branch 'software-clownery' into 'master'"

See merge request STJr/SRB2!616

This reverts merge request !578

Fix broken corona list

See merge request STJr/SRB2!605

Software clownery

See merge request STJr/SRB2!578

(Looks at 4865a190...)

Renderer switching

See merge request STJr/SRB2!550