Some minor cleanups
Stop sending the etag and lastmodified back to the server because they have no meaning in normal requests to the server (only in conditional requests)
Cleaned up RiakServerInfo and added a val containing the protocol
Removed testcases for the troublesome corner case of index names and index values that contain illegal characters, i.e. characters that will lead to unpredictable behavior when url encoded/decoded on both sides of the http connection

Both we (Spray) and Riak perform url encoding and decoding but http headers are treated differently, causing values containing things like commas and spaces (both used in headers as separators) to behave weirdly.

We might fix this in the future but it was holding back migration to the latest Spray milestone.
Rewrote the URI building subsystem on top of Spray's new Uri class

This does mean that we can now no longer support our (admittedly very heavy handed) workaround for dealing with indexes that contains characters that conflict with url encoding and http header encoding. For now this is accepted as a known issue.