UI: Add test datasets from Titan for GraphML & GML
Update file import to allow user-defined search indices

Obtain searchkeys parameter from POSTed form

Conflicts:
	src/main/java/org/lab41/dendrite/web/controller/GraphImportController.java
UI: Add ability to parse vertex keys from uploaded files
UI: Add file upload modal to select search indices when importing
Merge pull request #53 from kylef-lab41/pr-fileparse

Parse uploaded files for search index keys