add functional tests for graphs controller.
move MappingError into the class and rename it.
add submethod tests for GraphDataFetcher.
add logic-specific tests for GraphDataFetcher.
update bundled gems.
add factory for links.
add ontology-specific tests.
add missing GraphDataFetcher mappings.
replace remove shoulda matchers with asserts

- since shoulda 2.0 some matchers have been
  [remove](http://robots.thoughtbot.com/post/47031676783/shoulda-matchers-2-0).
load graph asynchronously when selecting a depth.
Simplified a test
activate graphs controller route for ontologies.
handle empty nodes and empty edges in graphs.
adjust graphs controller tests for empty results

- Test for return of valid response when calling
  graphs on logic/ontology without mappings/links
- Remove obsolete user portion (factory takes
  care of that).
Merge issue190... into augmenting112... for tabs

Merge 'origin/issue190-optimize_ontology_title_bar' into augmenting112_ontology_link_graph
Add Tests for determining Mapping-Class as Symbol.
implement passing version of mapping-query.
add graph as own view for graphs#index action.
Merge issue190... into augmenting112 for pages

Merge remote-tracking branch 'origin/issue190-optimize_ontology_title_bar' into augmenting112_ontology_link_graph
adjust js code to work with graphs#index view.