trap failure to delete non-existent featursets in OTF search
changed menu item to "Relaunch Zmap" and added key binding
New release tag humpub-release-73-03

Generated by /nfs/users/nfs_j/jgrg/work/team_tools/otterlace/release/scripts/otterlace_release_tag (otter/68-21-g0e32095 from ssh://git.internal.sanger.ac.uk/repos/git/anacode/team_tools)
MacOS: set XLOCALEDIR.