Added tooltip for 'use glonass station' checkbox in subSelection, changed
delay of tooltips in toolTip. Changed placement of all x-axis labels in
plotter. Force y=0 to show on data gap plot (in correction age plot).
Added function call of resetSelections in mainSelection's
*Clicked-methods, and changed the resetSelections-method in subSelection.
Fixed disabling of velocity radiobutton when Multiref-fix is un-ticked.
Fixed disabling of fields laying ahead of the button that's pushed.