Implemented natural string sorting for map and demo filenames (now so…

…rted like this: "e1m1, e1m2, e1m3, e1m10, e1m20" instead of this: "e1m1, e1m10, e1m2, e1m20, e1m3").

Fixed a crash when trying to read non-ASCII chars from worldspawn ent…

…ity of a .bsp inside a .pk3 archive.

Updated Readme.

Quake: improved .DEM reader compatibility (FTE/FTE2 demos support).

Quake, UI: renamed "Medium" skill to "Normal".

Updated SQL2_Readme.txt

Actually, let's call it 2.2

Quake: improved .DEM reader compatibility.

Optimized PK3 entries processing speed.

DemoItems sorting/colouring based on resource type.

Minor optimizations and fixes.