New Game+ for DOOM 2.1 file

The mod can be played like any other PWAD, by either dragging it on the source-ports binary or by selecting it with a frontend like a launcher or DOOM modloader.

v. 2.1 changes:
> minor armor & health stats overhaul
> minor enemy behavior & ability tweaks
> projectile speeds fixed
> startup health now bumped up to 90%
> minor ammo stats overhaul
> hitscan weapon behavior reset (bugfix measure)
> text string revisions
> smoke trails now rendered properly