Auto-format syntax

Ran the eclipse auto format to remove tabs and give proper
line endings
Generate HMAC signature for API request

In OTM2, most API requests need to have an X-Signature header
added which is modeled after Amazon SimpleDB api request signing [1]

This class generates the signature in the same fashion that the server
will be checking against request values.

[1]http://docs.aws.amazon.com/AmazonSimpleDB/latest/DeveloperGuide/HMACAuth.html
Update login endpoint to user

/login has been renamed /user as it reflects the actual utility,
since it returns user info, and does not actually 'log in'
Sign GET requests with HMAC

* Consolidate and simplify the various GET overloads
* Remove apikey in favor of access key and timestamp
* Sign request with HMAC signature based on req contents
Merge pull request #10 from OpenTreeMap/topic/api-request-signing

GET api request signing