Do a store copy on join when there are no log files for the latest transaction.

I tried writing a test for this, but SwitchToSlave is hard to write tests for,
so the fix is provided without one.
Docs fixes.
* Fixed bug in server plugin example.
* Fixed problem with bash syntax highlighting.
* Made the refcard entry on maps less confusing.
Merge pull request #2531 from chrisvest/2.0-merge-1.9

2.0 merge 1.9
Ensures that reused buffers of the batch importer are properly zeroed out

Batch importer makes use of a special window pool that reuses some of the
 buffers it requires. In some cases, it is possible for previous uses
 of a buffer to leave state in them, resulting in subsequent passes
 over the store to write out content that might cause problems
 later on. In particular, during store migration of a store that
 has large not in use record spans in it, it is possible that
 the target store would have contents in the same offesets that
 has not properly zeroed out records.
This fix ensures that when the buffer is going to be reused it
 is zeroed out first.
Merge pull request #2533 from chrisvest/2.1-merge-2.0

2.1 merge 2.0
Updates changelogs for 2.1.2
Document CSV file format

o add a documentation test about quoted strings and escape chars
Turn off execution plan documentation in 2.1
Merge pull request #2530 from nawroth/docs-fixes

Documentation fixes.
Merge pull request #2532 from davidegrohmann/csv-file-format-docs

Csv file format docs
Merge branch '2.1-maint'

Conflicts:
	community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyWindowPoolFactory.java
	community/kernel/src/test/java/org/neo4j/unsafe/impl/batchimport/store/BatchFriendlyWindowPoolFactoryTest.java
Fix problem about not using indexes when multiple labels are present on a node

o fix conflicts between Ronja rewriters and legacy planner
o added more index acceptance tests
o fix the legacy planner builder to make sure indexes can use values generated by unwind
Fix problem about not using indexes when multiple labels are present on a node

o fix conflicts between Ronja rewriters and legacy planner
o added more index acceptance tests
o fix the legacy planner builder to make sure indexes can use values generated by unwind
Add javadoc comments in the store layer, detailing correct use of the mapped store files
Merge pull request #2537 from digitalstain/master

Merge branch 2.1-maint into master
Typo in changelog for 2.1.2
Removed an incomplete log message. Should be properly done at a later point
Test accessing label changes in a TransactionEventHandler.
Prohibit using more than one hint per identifier
Readme cleanup in the distribution packages.