Allow returning the "old" rest format from the transactional endpoint.

For compatibility, in particular for existing clients, enable returning Nodes,
Relationships, and Paths in the "traditional" format of the Neo4j HTTP API.
This format also adds one level of indirection for returned maps in order to
be able to distinguish them from Nodes/Relationships/Paths...

This is implemented the same way as returning an extraction of the graph
in the result set. This format is specified as ["rest"] in the resultDataContent.
Introduce UnboundValue for keeping track of missing optional nodes.

o ClosingIterator.materialize converts UnboundValue to null
o Equality behaves correctly when comparing against UnboundValue
Fixed typo in linux-installer README

It is 'java-package', not 'java-packaging'
Merge pull request #1096 from apcj/2.0-optionally-exists

Introduce UnboundValue for keeping track of missing optional nodes.
First step in narrowing the gap between cypherdoc and graphgists.
Added note about legacy parser, and added ability to select legacy parser through config.
Use pattern matching for UnboundValue where sensible.
Ensure unbound values handled correctly by Cypher functions.
Merge pull request #1098 from jakewins/legacy-parser-docs

Docs for legacy parser
Validate uniqueness constraints for new data. In HA.

Support concurrent updates of data affected by the constraints on different instances in a cluster.
Acquire distributed locks to ensure mutual exclusion.
Adds moviedb cyperdoc example. Made sure there's always a console in cypherdoc pages.
Documenting semantics of unbound nodes in the manual
Skip write clauses if arguments of their patterns are unbound nodes.

* Handles SET, REMOVE, CREATE [UNIQUE], MERGE, DELETE and FOREACH
Make Desktop display license and install required license files.

o Moved launcher into subdirectory
Merge pull request #1100 from boggle/2.0-optional-actions

2.0 optional actions
Adding two more cypher tutorial pages.
Neo4j Desktop: Move license files up to top level.
Report '.' as expected where a property could occur

Error message will read "Expected '.', ..., ... or ..."
Merge pull request #1052 from thobe/2.0-rest-resultDataContent

Allow returning the "old" REST format from the transactional endpoint.
Fix compile error from previously merged PR