Added bytes_range option by default to lib/storage.stream_read
Added global options for storage plugins to implement bytes range
Implemented byte-range support on the local storage backend + unit tests
Implemented bytes range in boto_*
Serve Accept-Ranges header when needed
Parse bytes range in incoming request and pass right args to the storage lib
Implement range headers parsing + fix unit tests
Merge pull request #221 from dotcloud/bytes-range

Bytes range
Allow to specify elliptics namespace.
Rename configuration options according to typename-prefix style.

Also fix docs in README.md.
Merge pull request #222 from noxiouz/add_namespace_option_to_elliptics

Allow to specify Elliptics namespace.