Storlets should return 206 instead of 200 for Range request

[Takashi Kajinami]

When we request getting range of an object with storlet execution, storlet_middleware returns 200 OK.
However, based on RFC we should return 206 (or 412) for range request.

[Takashi Kajinami (kajinamit)]

RFC 7233 for range requests
https://tools.ietf.org/html/rfc7233

In the end of 3.1, it says the following thing
If all of the preconditions are true, the server supports the Range header field for the target resource, and the specified range(s) are valid and satisfiable (as defined in Section 2.1), the server SHOULD send a 206 (Partial Content) response with a payload containing one or more partial representations that correspond to the satisfiable ranges requested, as defined in Section 4.

[Eran Rom (eranr)]

Per discussion in https://bugs.launchpad.net/storlets/+bug/1534414
(following discussion in IRC)
we actually need to return 400 for X-Run-Storlet with range.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/283423

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/283423
Committed: https://git.openstack.org/cgit/openstack/storlets/commit/?id=194830a1f715c83ad18ab7c4ffbec0b4759b9253
Submitter: Jenkins
Branch: master

commit 194830a1f715c83ad18ab7c4ffbec0b4759b9253
Author: Takashi Kajinami <email address hidden>
Date: Tue Feb 23 16:21:13 2016 +0900

    Add X-Storlet-Range header to specify input range

    This patch introduces new header, X-Storlet-Range, which can be
    used to specify the range of the input object over which we execute
    storlet.

    Change-Id: I13f38a1588a995714508134c9ef3c7f49af17b21
    Closed-bug: #1534455