Bring develop branch ahead of master branch after code release.
Add links to ctools-00-07-00 and gammalib-00-08-00
Add ctools favicon
Adjust favicon name
Add link to GammaLib to glossary
Add information about cloning
Add link to gammalib spectral model documenation
Add missing hyphens
Merge branch 'integration' into devel
Correctly filter instrument and id attributes in ctobssim.

The instrument and id attributes provided by an observation were not considering when simulating source and background events. This has been changed now that only events will be simulated when the instrument and id are valid for a given model.