made metadata value generation more stable
display parent ontologies first
sort files: master file first
'ontologies defined by this file' are only shown in defining file
remove parens
show different icon on master file
only create an ontology if there is no master file yet
fix tests: ontologies are only created for the master file
optimize team_permissions query by using pluck

pluck allows us to extract fields directly from
a query without the need to instantiate model
objects (very expensive).
add spec to find the highest permission.
add methods to retrieve highest permission

- and use it for ssh-push access determination
- makes tests green.
Merge branch 'staging' into 538-correct-seeds-for-formality-level-etc
discussion at Skype conference with Maria Keet, Oliver Kutz, Aleksandra Sojic, Fabian Neuhaus, Christoph Lange, and Mihai Codescu
Merge branch 'staging' into 538-correct-seeds-for-formality-level-etc
Small cosmetic change.
Merge remote-tracking branch 'origin/599-fix_group_permissions_for_ssh' into staging
Merge branch 'staging' into 270-mark_master_file
Cleanup and Refactoring of Hets binding

now the LANG environment variable is set for execution of hets (solves #579, related to #622)