Implements some consistency checking for schema rules

o Check labels referred to by schema rules.
o Add SchemaRecord checking to DynamicRecordCheckTest.
Add further consistency checking of schema rules

o Verify rules are deserializable
o Verify rule uses known and valid kind
o Verify referenced labels
o Verify referenced property key tokens
o Introduce MalformedSchemaRuleException
o Verify that rule obligations match up
o Introduce SchemaRuleContent for semantically comparing schema rules
o Verify that the schema doesn't contain rules with the same content
o Properly handle ConstraintIndexRules without an owning constraint
Add support for consistency checking of schema rules to incremental checker

o The checking of schema rules is done through a full check of the schema store.
o Introduce SchemaRuleAccess interface for loading of schema rules.
o Introduce AbstractRecordStore<R> between AbstractStore and its descendants (except NeoStore).
o Added RecordSore.getRecords(id) and RecordStore.getNextRecordReference(id).
Merge pull request #950 from apcj/2.0-schema-consistency-check

2.0 schema consistency check