5.2012.05.14	
	bug fixed: interpolation algorithm corrected.

5.2012.05.16
	bug fixed: "dead zone" and "delay" fields are taken into account.

5.2012.07.10

	new: Database records displayed in the data table are now always sorted by "VP1",
	     "Date", "Time", and "Local" columns (in that order), regardless of their
	     actual physical position in the database file.

	new: Group check box toggling has been impletemnted in the "Mark" column 
	     of the data table: if a large number of consecutive measurements have to be 
	     selected or deselected, the user may click the first of the required check 
	     boxes and then extend that selection or deselection by clicking the last 
	     of the required check boxes while holding a Shift button.

5.2012.07.30

	new: Calibration time parameter now may be specified for measurements in digital
	     mode during an average operation (via "calibration t (ns)" input field).