Double Barrel add-on addon - D3_gameplay_fixes mod for Doom III

This mod is a compilation of fixes for Doom 3 base, that does just this, fix many of bugs found in the standard, default Doom 3 base, specially in defs and scripts, but also on materials, particles and so on. Also it adds some new stuff, like particles, materials and effects. This mod is not something spectacular with big changes, but is some even inperceptible changes and additions, that fixes small and big bugs and make Doom 3 the most perfect basis for the hundreds of mods available, so every mod runs much better and smoother with this fixes.