Changed label from "Point" to "Point(s)" to clearify that it is possible to select multiple points at once.

/ Float offsets are now integrated into the table
/ Options to either use manual or calculated offset (last one not done yet)
/ Added begin and end offset for soundsources to enable input of drift (drift not implemented yet)
/ Updated GUI of track parameter

The X-Axis of the edit TOA window is now synchronized with the zoom in trajectory output window if selected.

/ Changed background color of axes to white
/ Changed colormap to gray skipping the first 44 steps of 300

+ Added checkbox to enable mercator projection
+ Added checkbox to show/hide position dates
+ Extended position dates by rafos day
+ Added colors for trajectories
/ Improved soundvelocity caluclation
+ Added clock error calculation

+ Added soundsources/colorregister package that is used to assign a color
  to a specific sound source.
+ Added an edit field to the upper and lower boundary adjustment section
+ Added a histogram plot of the TOAs
/ The soundsource color legend shows only the color of an applied sound
  source, white otherwise.

Bugfix:
  When soundsource has been applied, the zoom function was not functioning
  anymore.

Toa table:
  It is now possible to select the duplicates in the toa table, and the
  the plot will zoom to it.