Sectors mode: added "View Tags and Effects" button.

Sectors mode: effect and tag overlay can now be toggled separately from selection numbers.
Sectors mode: "View Tags and Effects" and "View Selection Numbering" settings are now saved to program configuration.
Sectors mode: removed "Lower Floor by 8 mp", "Raise Floor by 8 mp", "Lower Ceiling by 8 mp" and "Raise Ceiling by 8 mp" actions.
"Increase Brightness by 8" and "Decrease Brightness by 8" actions now work in Sectors mode.
Moved "Increase Brightness by 8" and "Decrease Brightness by 8" actions to "Edit" category. 
"Toggle Highlight" action now works in Sectors mode.
Moved "Toggle Highlight" action to "Tools" category.
Removed Brightness mode.
Updated documentation.