wsgi.Middleware forward-compatibility with webob 1.2b1 or later

Response.request is None by default
(http://docs.webob.org/en/latest/news.html#b1), but is used in the
CacheFilter WSGI middleware.

Backport of https://review.openstack.org/#/c/17794/

Change-Id: I28f5ca92fe517f4f56af934799db32650e079ba7
Verify size in addition to checksum of uploaded image

Fixes bug 1092584

Previously only the supplied checksum was verified against the actual
checksum calculated by the backend store, with the image being killed
on mismatch.

Now we also similarly verify the supplied image size, if provided.

Change-Id: I87fa3ff77715111f1095f3ebe64cd699776ec27e
Log error on failure to load paste deploy app.

Fixes bug 1091294

Avoids possible silent failure of service launch when say a
dependency such as keystone is missing (but required by the
configured paste_deploy flavor).

Change-Id: I9a63d24bcf0a93277829d24073268210d2c063d3
Merge "Verify size in addition to checksum of uploaded image" into stable/folsom
Merge "wsgi.Middleware forward-compatibility with webob 1.2b1 or later" into stable/folsom