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
manually create db-connection on test:purge.
Merge pull request #1101 from ontohub/fix_test_db_building

manually create db-connection on test:purge.
enforce hierarchy-sentences to end appropriately.
Merge pull request #1102 from ontohub/1100-fix_tree_generation

enforce hierarchy-sentences to end appropriately.
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.
Remove empty importing_test.
Move repository_test to rspec.

The context 'saving a file' was already moved, but not deleted from
the _test.rb file.
Move autocomplete_test to rspec.
Remove empty basic_proof_test