ctools

The current version is mangled

outfile <SLICE|NODES|AUTO> [file]
Spectrum generation method.
SLICE: Slice energy interval into enumbins independent bins.
NODES: Replace spectral model by node function with enumbins nodes.
AUTO : Automatically select method based on input data. Will use SLICE
for CTA-only observations and NODES for observations including
non-CTA data.

Need to add description of outfile, and move this description to the parameter method.