Michael Mayer / ctools

…served events in ctlike.

… ctcubemask for this purpose

…ontribution is expected.

According to a study by Stephan Fegan done in the context of Fermi/LAT analysis, the best way to determine a butterfly diagram is to draw the envelope of the error ellipse of the model parameters. I implemented this method now in ctbutterfly. I also changed the output file, having now two columns giving as function of energy th minimum and maximum intensities.

Conflicts:
	examples/show_butterfly.py

Without the energy margin, roundoff errors may lead to the exclusion of the energy bin in case that a single energy bin is used.

…d in observation ebounds. Also added some improvements to csspec.

…no selection was performed)

Conflicts:
	scripts/csresmap.py