With a little help from my friends

This release changes:

• The signature of the mutate function which incorrectly took a single vector but now takes varargs in the same way as query #55 (thanks @loomis)

This release adds support for:

• Synchronous mutate and query (Clojure only) #56 (thanks @loomis)
• Specifying the websocket sub-protocol #53 #62 (thanks @jmarca)
• Aborting operations via HTTP (experimental) #50

This release improves:

• Error handling will no longer overwrite the status or message from the server if they are present #54 (thanks @loomis)
• The examples in the readme #57 #61 (thanks @viebel)