Snipers Only & Junkland Map

2021 05 09 (smallest to biggest changes)..
- new textures: cinder blocks, dirt, lab walls
- testing: junkland map with new random types
- testing: tree physics / bullet passing
-- new mode: snipers only (with smokes)

2021 04 16 (smallest to biggest changes)..
- changed smoke grenade tracers to streamers
- changed tracers for rockets to transp smoke
- misc texture adjustments and code polishing
-- requested: Grenades Only a permanent mode