Fog

This release is mostly internal changes and fixes, most notably the new build system allowing me to program for 1.20.1, 1.20.2 and 1.20.3/4

• Fixed issue with fog being inverted [1.20.2]
• Fixed issue with configuration screen not being closable after saving.
• Fixed issue with cave fog colouring not being applied.
• Fixed issue with crashes on rejoin due to FogManager not being reapplied correctly.