Changed "Raise Floor by 8 mp" and "Lower Floor by 8 mp" default shortcuts to "Ctrl-Alt-ScrollUp/ScrollDown", because they used the same keys as "Increase Brightness" and "Decrease Brightness" actions.
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.
Increased maximum zoom level in Classic modes to 3000%.
Added "1 mp" option in grid size menu.
Added "400%" option in zoom menu.
Renamed "Toggle GZDoom rendering effects" action to "Toggle Geometry Effects".
Sync camera position: Visual Camera height is now changed only if camera is above or below current sector.
Classic modes: view was not redrawn after "Test map from current position" action.
"Test map from current position" action: incorrect player start was used when a map had several Player 1 Start things.
