Info panels: thing and sector flags are now displayed.

Visual mode: changed "Move Texture Left/Right/Up/Down by 8" actions to "Move Texture Left/Right/Up/Down by cur. grid size"
Visual mode: holding Ctrl-Shift while dragging texture with the mouse will snap texture offsets to current grid size.
Classic modes: interiors of highlighted sectors are now highlighted when the action target of currently highlighted map element is sector.
Unhandeled exceptions infos are now written to the event log.