Minor fix to clustering tutorial formating.
Minor updates to Cypher documentation.
Time out instead of block indefinitely.
Fix for problem with index lookups against properties

Index lookups use expressions to dynamically produce the value
being searched for. The expressions might have symbol table
dependencies that are not met, and in these cases Cypher should
not use index seeks. This commit makes it so.
Merge pull request #1633 from nawroth/cypher-fixes

Minor updates to Cypher documentation.
Documentation updates
Updated the note on MERGE being new.
Merge pull request #1636 from systay/index-expression-deps

Fix for problem with index lookups against properties
Re-order documentation sections for better readability.
Merge pull request #1638 from apcj/2.0-ha-docs

HA documentation