Merged two Clock interfaces into org.neo4j.helpers.Clock and removed unnecessary implementations
recreated traverser framework api classes  org.neo4j.graphdb and org.neo4j.graphdb.traversal and deprecated the ones in org.neo4j.kernel and subpackages
created new PathExpanderBuilder for buiding specialized PathExpander instances
created new PathExpanders catalogue of convenient PathExpander factory methods, and deprecated corresponding convenience methods in Traversal
opened up StandardExpander for use public use instead of just package private use
added (Bidirectional)TraversalDescription factory methods in GraphDatabaseService
Hid Javadocs for org.neo4j.kernel and subpackages
Introduce nodeGetUniqueFromIndexLookup

o Introduce StatementConstants.NO_SUCH_{NODE, LABEL, PROPERTY_KEY}
o Introduce uniqueIndexGetForLabelAndProperty
o Take an index lock for nodeGetUniqueFromIndex
o Exposes nodeGetUniqueFromIndex from Cypher as exactUniqueIndexSearch
o Rename SafeProperty to DefinedProperty
Merge pull request #1167 from boggle/2.0-merge-locking

Introduce nodeGetUniqueFromIndexLookup
Merge pull request #1156 from lassewesth/fixinternalapi

Fixinternalapi
No need to check for data changes now that transactions disallow them.

Transactions now prevent a user from making data changes and schema changes in
the same transaction, so there's no need to look for data changes when creating a
unique constraint.
Allow cypher to read data and modify schema in the same transaction.

This is achieved by delaying the choice of statement type (data write vs schema write)
until specific operations are required.
Remove concept of QueryType from Cypher.
All kernel operations are accessed through a single Statement API which in turn
exposes narrower interface for read, data write or schema write operations.
Statement objects need to be closed, but indivdual operations objects don't have any
additonal state and so don't need to be closed.
Extract narrower interface for Statement.

Hides internal state from clients of the kernel.
Return Statement instead of its implementation.

For better encapsulation.