Language update

Added many new functions, keywords, predicates and operators (based on http://docs.neo4j.org/refcard/2.1.2/). Added ".cypher" as an acceptable file extension.
Classified keywords

The list of keywords was too long. Broke it down into shorter lists.
Fixed and issue with composite "CREATE" keywords
Fixed and issue with NULL, TRUE & FALSE constants
Updated aggregation functions and modifiers
Fixed USING PERIODIC COMMIT and WITH HEADERS
Merge pull request #1 from mszargar/master

Neo4j 2.1.2 and modified Cypher syntax