Do not set -Xmx1g in install4j as that can prevent user customization
Put Ignore annotations on compatibility suite classes since they aren't
run directly, something that the annotation message says as well.
Allow data read operations in any transaction.

Previously data read operations were not allowed in schema transactions,
but the only important restriction is to disallow data write operations and
schema write operations in the same transaction.
Correct behaviour when committing a transaction fails.

When a transaction fails to commit, it should still be possible to roll it back.
Added optionality to nodes on the AST object
Added functionality to infer and mark nodes as optional
Made sure we infer optionality on UNION queries
Minor clean ups
Connected the optionality inferer
Handles Cypher 2.0 queries without start point and optional pattern elements
Adds rewriting of queries, pulling out predicates from mandatory nodes to the WHERE clause