split diff per file
introduce DiffsController
remove diff action from files controller
split diff computation into many small functions
add specs on DiffsController
add spaces around assignment operator
shorten line
clean the code, fix diff of first commit retrieval
Merge branch 'staging' into 865-introduce-diffs-controller
Merge pull request #1055 from ontohub/865-introduce-diffs-controller

865 introduce diffs controller
change fixture_file ontology-call to ontology_file.
Merge pull request #1112 from ontohub/fix_fixture_calls

change fixture_file ontology-call to ontology_file.
set the label as display_name for obo-symbols.
return the query-hash, not its last element.
save entity/symbol only if it is not null.
add migration to update display-name for obo

The symbols of obo-ontologies need an update.
This also pertains to the generation of
the class-hierarchy tree.
obey hound.
make hound obey - for migrations

Methods in Migrations are allowed to be longer.