generate logic-mapping-graph with JIT see #138
logic-graph with depth see #138
unmess code and improve visibility of jit-graph
LogicMappings-graph in both directions
use thejit as gem and add context-menu
use coffeescript
use jit only when needed
add sql-based method for determining graph nodes.
Merge branch 'master' into graphs
adjust logic-fetching sql for logic-graph-nodes

- Use With-Clause instead of temporary
  table (Select Into).
remove mysql-gem from Gemfile

- We actually use PostgreSQL now, so
  we don't need the mysql-gem anymore.
Extract graph-data fetching into own class

- Since we can reuse the idea for fetching
  the graphs nodes in ontologies, this
  extracts the functionality into
  its own flexible class.
adjust GraphDataFetcher to fetch nodes and edges.
add controller for graph data.
remove obsolete graph-generation code.
add d3 support via Gemfile.
add d3 based graph generation code

- this code is asynchronous and loads
  the graph after the html-page is loaded.
add methods to fetch active ontology versions.
actually show only ontologies with done versions.
show ontology state pertaining to user, #index.