Reverted "Delete Item" action to the way it worked in DB2.
Added "Dissolve Item" action, which works the way "Delete Item" worked in previous revisions of GZDB.
Added "Auto Clear Sidedef Textures" action, "Edit" menu and toolbar button, which toggle automatic removal of sidedef textures when floor or ceiling height is changed or when geometry is drawn, copied or pasted.
Draw Settings panel: upper/lower texture overrides can now be used.
Draw Settings panel: added 2 sets of buttons, which allow to quickly set or clear textures in current selection.
Things are now rendered behind AND on top of the grid/linedefs/vertices when they are dragged.
Redesigned hints system. They are now shown in a side panel.
Edit area auto-focusing is now disabled when script editor is open.
Texture Browser form: no texture group was selected when opening the form in some cases.
Fixed several strange/misleading text messages.
Floor and ceiling textures are now moved more predictably by arrow keys in GZDoom Visual mode.
Walls texture coordinates are always rounded when moved by arrow keys in Visual modes.
Linedef info panel: relative UDMF light values are now shown like this: 16 (128), which means "UDMF light value" ("total surface brightness (UDMF light value + sector brightness)")
Player is now spawned at camera height when testing from current location in Visual modes.
Focus is now properly restored after testing from current location in Visual modes.
Updated Heretic_sectors.cfg and Heretic_things.cfg as described here: http://www.doombuilder.com/forums/viewtopic.php?f=11&t=357
Changed sprites of artifacts in Hexen_things.cfg to proper ones.
Renamed Skulltag configs to Zandronum
