lightning beams have been replaced with a polygon effect which renders faster than...

lightning beams have been replaced with a polygon effect which renders faster than the model effect and looks...  oh umm... about 100x better, old effect still available - cl_beampolygons 0 to go back to models - some r_lightningbeam_* cvars added for tweaking new effect
r_speeds now reports some realtime lighting info
shadowless light support added
(unsuccessful) attempt to fix r_drawportals by moving the call to happen whether portal rendering was used or not
comment about possible optimization to shadow volumes added (rather, inverted light volumes and how to get maximum performance from them)
light styles are now checked for validity (must be in the right number range)
tiny cleanup to cubemap name handling (cubemaps are still not actually supported)
r_editlights_rtlightcolorscale and sizescale are now applied only in LoadWorldLights and SaveWorldLights, not in light creation (also somewhat to compensate for this fact, .lights loading has been tweaked to double the brightness)
torch light colors changed (more orange)
r_editlights_spawn no longer takes parameters
r_editlights_edit now has subcommands instead of setting all properties, the commands are: origin, originx, originy, originz, move, movex, movey, movez, radius, color, style, cubemap, shadows
r_editlights_toggleshadow added (useful for point and click shadow toggling)
display overlay now shown when pointing at a light in editing mode, indicating all properties of the light

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2701 d7cf8633-e32d-0410-b094-e92efae38249