Export user graph as table

[b]

Add an "export" button that saves all of the triples in the user's network view in a 7 column, tab-delimited table. Column headers: Subject id, Subject label, Predicate id, Predicate label, Object id, Object label,PMIDs

This will allow advanced users to regenerate their graphs in cytoscape and other tools. Should also be a stepping stone towards user-graph management that does not require account management.

[Richard Bruskiewich]

Baseline implementation exports both a tab delimited data file plus some query meta-data and a JSON representation of the concept map for reloading/

[Richard Bruskiewich]

Baseline concept map save/load implemented. Perhaps a future iteration of this functionality can split out the 'data' export (for external data analyses) from the 'concept map state' export (for reloading)