Reinstated a DataSourceManager

that adds registration listening to the neostore data source.
Fixes UDC to run w/o JTA
UDC fix for real this time
Some test compilation failure fixes

as well as corrections to make them pass, specifically around some
internal use of KernelTransaction and startup sequence
Management fixes and more
Moved getAllNodes/getAllRelationships into kernel API
Documentation fixes for 2.1.

* Added UNWIND to refcard.
* Better links to other resources.
* Typos.
* Added refcard the docs build.
Updates changelogs for 2.1.0
Remove errant definition of additional artifact for UDC integration tests.
Updates changelogs with memleak fix
Adds memleak fix to changelogs
Remove errant definition of additional artifact for UDC integration tests.
Merge pull request #2466 from benbc/2.1-fix-udc-maven-problem

Remove errant definition of additional artifact for UDC integration test...
Removed unnecessary argument
Merge pull request #2467 from benbc/2.0-fix-udc-maven-problem

2.0 fix udc maven problem
Merge pull request #2463 from chrisvest/2.2-future

Refactorings and data-race fixes for the standard PageCache
Added additional protection for IO exceptions when flushing pages.
Fix a bug where flushing a page with a given PageIO could race with eviction
Merge branch '2.2-future' of github.com:neo4j/neo4j into 2.2-future
Added check to ensure we don't re-pin with a cursor already using another page.