Create node/relationship index with configuration

- A 2nd parameter, which accepts a index config object, to
createNodeIndex/createRelationshipIndex methods is added
- Overloading helper for both methods is added
- Fulltext with lowercase & fulltext with no lowercase support tests
are added.  Total of 4 different test cases added; each testing two
configs for both node indexes and relationship indexes.  Partial fuzzy
(fulltext) searches are performed in these tests.  Existing tests are
not modified, just new ones are added
- Nodes & relationships which are added to index are now deleted after
tests are finished (it was a todo from previous commits)
- There was no queryRelationshipIndex method which is required for
querying fulltext relationship indexes in lucene query language, so I
implemented it.  I saw that it was a todo, so I deleted todo comment of
queryRelationshipIndex method now that it is implemented