Use JSON for search index key selection
Index edges into ElasticSearch
UI: Parse and select edge keys for search index
UI: Update 'select all' text to avoid confusion
UI: condense sort function for readability
UI: remove double-refresh on vertex list load
UI: use ElasticSearch for Edge list

TODO: ES currently fails to index all edge properties
stored in Titan, which requires a series of queries.
Ensuring ES indexes all edge properties would eliminate Step #2:
1. ES returns list of edges
2. Query Titan for each edge in list
3. Query Titan for vertices in each edge for usability
Remove ES field _edgeId since it correctly indexes Titan id
Merge pull request #104 from kylef-lab41/pr-elasticedgesfix

UI: use ElasticSearch for Edge list