Iftach Sadeh / ctools

This avoids any conflicts with the pfiles directory that will be created during unit testing.

The current script covers all 1DC tutorials.

…new refitting logic, and revert back to original reference values for the unit tests

The "refit_if_failed" parameter instructs ctlike to perform a refit in case of a fit failure. Fit failures are either a stalled fit, an exhaustion of the number of iterations, or a significant difference between the number of observed and predicted events.

# Conflicts:
#	doc/source/users/tutorials/notebooks.rst

Update 'test/data/spectrum.fits' to use the new column names

# Conflicts:
#	ChangeLog
#	NEWS
#	README.md

Add tests to csbkgmodel for multi-instrument observations (#2862)

This allows setting the exclusion map without having to save the map first

This enables accessing the generated skymaps without calling 'save()' first