Dynamic lights defined in GLDEFS are now rendered in Visual modes (currently only one light per Thing is supported).
Several values from (Z)MAPINFO are now used in Visual modes.
Added "Reload GLDEFS", "Reload (Z)MAPINFO" and "Reload MODELDEF" menu options (in "Tools" section).
MODELDEF parser now checks which model(s) is/are used in first frame.
Dynamic lights are now created with more meaningful default parameters.
Added errors and warnings indicator to main window.
