Johan Bregeon / ctools

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

…definition, one of the erg_mean is replaced by e_mean

…tion by a factor of 20 w/r to the counts cube.

Also document the new anumbins parameter.

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

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