Merge branch 'release/0.2.20' into develop
Minor: clean on postpublish now!

Npm used to run postpublish scripts in a temporary dir used for publishing,
which wasn't useful here.

That's no longer the case, thanks to:

https://github.com/isaacs/npm/pull/3053

So we can clean up our compiled CoffeeScript-Streamline code here now. Sweet!
added unindex function for nodes
got unindex to work, removes all key/value pairs in index matching the node id
unindex now supports optional key/value paramaters
added get/create/delete node index functions
added indexUniquely for nodes and added all new index functions to relationships
added unindex function for nodes
got unindex to work, removes all key/value pairs in index matching the node id
unindex now supports optional key/value paramaters
added get/create/delete node index functions
added indexUniquely for nodes and added all new index functions to relationships
error handling if there are no indexes
added index tests, fixed some bugs, removed js files
removed indexUniquely since it's no longer in the API (1.9.M02)
Indexing code cleanup and minor API refinements.

In particular, get{Node|Relationship}Indexes() now returns an array of string
names rather than a straight map, but has the map properties too.
And it returns an empty array in the 204 case rather than null.
Unindexing code cleanup.

Somehow there were two Node::unindex() functions; removed one.
Remove Node::indexUniquely() method.

This capability -- adding an *existing* node to an index unless one already
exists -- has been removed in 1.9. Sad day. =/

Thanks @flipside for both contributing this implementation and then giving a
heads-up that this is no longer possible.

Closes #14 -- we're going to have to wait til Neo4j 2.0's new indexing
framework, which will hopefully re-enable this (ideally via Cypher).
Add indexing features to changelog!
Merge branch 'feature/indexing-enhancements' into develop

This is @flipside's pull request #55 + some minor cleanup and improvements +
update to the changelog. Many thanks, @flipside!