Changed: "Unable to save the map: there are too many unique sidedefs!" error...

Changed: "Unable to save the map: there are too many unique sidedefs!" error message now displays info about sidedefs counts before and after sidedef compression.
Fixed, Draw Grid mode: in some cases invalid geometry was created when drawing very large grids.
Fixed, Things mode, "Rotate Clockwise" action: fixed inability to change thing angle from 0 to 315 when "doomthingrotationangles" Game Configuration property was set to true.
Updated ZDoom_DECORATE.cfg.