gscreen -fix error message if move-to button pressed

If you were in the override selection and pressed this button
you got an error.
gscreen config -change some gui elements for aesthetics

LED colors, text placement etc
gscreen -add support for an alarm page

This prints the current local time and any messages sent to the notify method
to a textbuffer to be shown as an alarm page.
gscreen config -added features to industrial screen

direct tab selection buttons
alarm history
docs -start to add info about new gladevcp widgets