User Interface:
- Let user select smaller wavelength range than 10A!
- Make spaxel selection much faster by only redrawing the one spaxel (and
  perhaps the adjacent ones)
- Add WCS to spaxel coordinate display in spaxel viewer, including correct
  coordinates in saved GIF maps etc and a north-east indicator in all modes
  --> this would be hard!
- Let users do spectral arithmetic with the mouse, too (as it was before?)
- User preferences: window position, color table, and other stuff from
  "Configuration" menu
  --> this would be great, but lots of work. Will probably not happen for
      E3D but rather for its successor
- Clean up the mess with the cuts that influence the other windows, too
  --> looks like a lot of work, postpone for the E3D successor

Bugs and possible bugs:
- Copy all FITS headers on export
- DAR gives 100% CPU for a long time but no obvious result or other reaction
  => All DAR modes only seem to work for objects with bright continuum?
- hang after pressing "v" in pseudo-slit selected object
  --> reproduced consistently, but didn't find out what is causing it.
- Wavelength display after line fitting in top notification area is
  between 0 and 1 and not real lambda
  --> looked at this but don't know how
- Sometimes the scale in the main window is overlayed by the RSS
  --> couldn't reproduce in a way so that I could track it down
- When loading spaxel viewer (or new view in spaxel viewer) some spaxels are
  marked (initialization problem?)
  --> couldn't reproduce in a way so that I could track it down
- Sometimes when "scrolling" in the main window the display doesn't clear
  and then looks garbled?!
  --> couldn't reproduce in a way so that I could track it down
- Saving spectrum in Spectra Inspector overwrites previously saved spectrum?!
  (already since 1.3a or so)
- Saving spectra does not always work
  (error message is 'invalid command name "lset"')

Ideas:
- Let it (any2Euro3D etc.) really write CIRCLE etc (not just C) into the groups
  header?
  --> Is this really what is required by the Euro3D Data Format specs?
- Change any2Euro3D so that it can handle more than one group
- Get rid of the many tools and just let them call any2Euro3D with the right
  parameters and postables for the respective instrument

Buildconfig wishlist (probably all postponed to E3D successor):
- Redesign directory structure (no more extra obj dir, no more user/bin)
- Redesign ./configure stuff to actually do something useful
- Link LCL as shared library and then link to that (minimize binary size)

