REST and Core APIs now support listing all stored property keys in the db.
Merge branch 'list-keys' of github.com:jakewins/neo4j

Conflicts:
	community/kernel/src/main/java/org/neo4j/kernel/api/ReadStatement.java
Make test more stable by avoiding triggering bug in index population.
Enable schema changes on master of HA cluster.

Remove HA concept from kernel; replaced with SchemaChangeGuard.
Replace ReadOnlyStatementOperations with guard on upgrading
transaction for data write or schema write.
Change (default) in-memory index impl to be list based.

This would be useful for exposing issues where duplicate entries are added to an index.
Currently no test cases expose such a case.
License headers.
More license headers.

Also put UniqueConstraintHaIT to its previous state.
Acquire statement inside transaction.
Address PMD import warnings.

Removing unnecessary fully qualified names.
Specify parameter for static import check to allow up to 10 static imports per file.
Remove the last references to deprecated Transaction.finish() from production code.
Remove unused old ShortString stuff.
Remove some calls to Transaction.finish() from test code.