relighting v4.0164b file

v4.0164b

6/15 - added floorshadow actors for "blurry" shadows similar to wall shadow actors
6/15 - added distance check for shadows behind the player
6/16 - added rl_blur_shadows CVar
6/16 - corrected rl_lifespan in shadow Tick() function
6/17 - adjust warea limit for texture baking by sidedef variables
6/18 - tweak strength of decorative/texture lights

Shadows aren't really "blurry" - impossible with sprites - so much as projected to floors and ceilings like wall shadows. This effect can be turned off in Settings.

The rl_lifespan CVar has been corrected and increasing this will improve performance at the cost of shadow smoothness.