Make Cypher execution results closable

o Introduces ResourceIterable/ResourceIterator
o Makes ExecutionResult implement ResourceIterable
Merge pull request #833 from systay/closable-execution-result

Make Cypher execution results closable
Fixes broken syntax in docs.
Clean up of SlicePipe
Change to use "keep" for line endings. This will retain double line endings from source.
Merge remote-tracking branch 'origin/master'
Changed the wording on the haproxy doc so that it doesn't seem like we're advocating write-through slaves
Introduce BenchmarkCommandLineInterface.

QuickReadPerformanceTest is first example of a test implementing
low-tech command-line interface.
License headers.
Fixes races condition in getSingleRelationship().

Added test that checks for duplicate entries in the iterator returned by getSingleRelationship. If the iterator contains multiple identical entries, then silently swallow any barf and return the first as the user expected.

Note: this commit is a bit of a band-aid since we really need proper isolation in the kernel. The test and the code likely should be removed in some future state.
Tidied up the unused parameters in NodeImpl.
Add more simple benchmarks.