Implemented HTTPRangedByteAccess.

HTTPRangedByteAccess supports HTTP range requests for ranges of resources. Includes a test
that executes against a few bytes of the test mouse chromosome on the berkeley server.

(Matt or Frank, check out the additional test case in ByteAccessSuite, let me know if using the URL of the mouse_chrM.bam, which is the same bam as used in the integration tests, is okay here in the unit tests too.) 

This branch is a precursor to fixing the tests / integration tests on the big Parquet / RDD PR.
The [206](http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.2.7) is a Partial Content response. Although, I'm unsure of whether we'd get a 206 if the range is the whole entity. @tdanford do we always expect a 206, or is this just because we are doing a partial request?