Simple State object test coverage
Improvements to XDomainRequest handling around aborted requests
Correct handling of Content-Type header

* Breaks backwards compat, no longer send 'application/json' in every
  request
* Default to sending 'application/octet-stream' for document APIs when
  no content type is specified
* Add basic activity profile test coverage
* DRY TinCan unit tests for version loop
* Add setting etag during State construction
* Adds special handling for when content type is 'application/json',
  for automatic serialize/deserialize of objects
Minor syntax cleanup
Implement AgentProfile
Correct handling of aborted, offline, and CORS denied requests

* Add unit test coverage file for testing LRS .sendRequest in specific failure
  scenarios where an HTTP status of 0 is hit
* Adjust alert warning message depending on http status being 0 or not
Round out options to TinCan constructor and docs