Build 181123

It's been a real while since the last build so I can't really recall the whole list of whatever has been done (it was... a lot).

WARNING! (Not) very long first-boot time, because I'm tired of packing the whole cache.

• Numerous visual upgrades (both models and shading);
• Better Map2;
• Improved performance;
• Higher particle count limit;
• All the missing directories are created whenever needed;
• Weapons tweaked, including railgun range and velocity;
• Many minor bugs fixed;
• LUT swaps no longer require the matching shader to be initialized (if needed, the shader is re-built);
• Lighting modulation;
• Custom map scripting;
• Better menus etc;
• Custom indoor levels;
• Audio tweaks.