Fix delete versioning objects when previous is expired

When deleteing versioned objects proxy will try to restore the previous
copy. The COPY request will fail if the previous version is expired but
not handled by object-expirer.

This patch checks COPY respones on the previous copy, if it's
HTTP_NOT_FOUND(mostly because it's expired) proxy will try to restore
with the version before previous.

Closes-Bug #1308446
Change-Id: I17f049ea3ef62723effae8086ec427f6e151cd9c
Allow filtering by region in swift-recon

The option "-r" is already used, thus only "--region" is used to specify
filter by region.

Change-Id: If769f2f3191c202933b03b48fe0f22b7c94a4dd6
Closes-Bug: 1369583
Merge "Fix delete versioning objects when previous is expired"
Move multipart MIME parser into utils

Over on the EC branch, we need to be able to parse multipart MIME
documents in the object server. The formpost middleware has a
perfectly good MIME parser, but it seems sort of awful to import
things from formpost in swift/obj/server.py, so I pulled it out into
common.utils.

Change-Id: Ieb4c05d02d8e4ef51a3a11d26c503786b1897f60
Merge "Allow filtering by region in swift-recon"
Merge "Move multipart MIME parser into utils"