Introduce new DocBuilder abstraction fo bundling RecursiveDocGenerators with their DocGenerator

o Remove SimpleRecDocGen
o Remove NestedDocGen
o Rename RecursiveDocGen to NestedDocGen
Convert doc builders to be easily chainable as a flattened list of partial functions by introducing DocBuilderChain
Label support for astExpressionDocBuilder
Rename pprint.docGen => pprint.docbuilders
Add pages for forcing use of line breaks in a group
Add logicalPlanDocBuilder
Replace string visitor with pprint
Add support for logical connectives and numerical comparisons to astExpressionDocBuilder
Reorganize Doc helpers for breaks and remove some dead code
Fix query graph indentation
Reorganize Pretty trait and Doc helpers
pprinting of ast literals and function invocations
Change quote{String|Char} to match up with Cypher manual
Add prettyDocBuilder for allowing instances to render themselves directly
Merge pull request #2431 from boggle/pp

pprint: cleanup, docgen caching, logical plans
Merged commit 9079426036c5cf9f9953c1349717aeea8d21fed3

Fixed bug that caused RWLock not to free up entries in txLockElementMap.

The mark flag is used to guard against creating multiple RWLocks for the same resource and has nothing to do with TxLockElement entries.

TxLockElement creation and removal is still safe since it is synchronized on the RWLock.

Conflicts:
	community/kernel/src/main/java/org/neo4j/kernel/impl/transaction/RWLock.java
Quick fix for udc tests
Merge pull request #2461 from johan-neo/master

Merged commit 9079426036c5cf9f9953c1349717aeea8d21fed3
Updates changelogs for 2.1.0
Remove errant definition of additional artifact for UDC integration tests.