* Updated the EE config linedefs, fixing stuff around
* Added back the class definitions for the Eternity namespace
The only namespaces where they're unneeded are the vanilla games. Otherwise it's safe and important to keep class1, class2, class3 in case Hexen pops up
* Added new special (273) to UDMF Eternity linedefs
* Added special 140 to the Eternity linedefs
Probably fixed probable I/O race condition when loading images.
Fixed Visual mode stuttering due to floating point precision degradation when running the editor for several days without restarting (internal timer is now reset when saving the map or creating a new one).
Fixed, Nodes Viewer, cosmetic: Nodes Viewer window position was reset after pressing the "Rebuild Nodes" button.
Added Eternity Game configurations by printz.
Updated ZDoom_ACS.cfg (CheckClass).
Updated ZDoom ACC (CheckClass).
