Kymograph analysis march 12th

Small fixes for Dundee user of Kymograph scripts.
To test:
 - Draw a line on a movie image (chose one with time-stamps E.g. DV) and run Kymograph script.
 - New kymograph images named as <original-image-name>_kymograph
 - Draw line(s) and polyline(s) on the Kymograph. Run Kymograph_Analysis on this:
 - The csv file should show the name of the kymograph and image ID
 - Last 4 columns should be: x/t, speed, avg x/t, avg speed.