Merge branch 'ausachov_etab_photondaughters' into 'master'
Add etab->gamma gamma with photon daughter cuts
See merge request !1316 (merged)
(cherry picked from commit 74a5cab8)
4ac23081 add incl_etab,gammagamma=PhotonDaughtersInLHCb.dec 7dcd1c86 make it simpler 9e6ecda4 cleanup