Alexander Ziegler / ctools

Convert the cta_root2caldb.py script into a cscript and add unit test. The script only works if PyROOT is installed.

Instead of the cta_root2caldb.py script a generate_prod3_irf.py script was added to the example folder.

Also some code speed up by considering only relevant pixels for radial and elliptical models.

# Conflicts:
#	cscripts/cslightcrv.py

…etting up the unit tests.

# Conflicts:
#	cscripts/cta_make_nodes.py

…or 1 (STDOUT) to /dev/null.