Set objects indirection API in metadata service

Commit Ia12f48227eb2380f5da93313cd4045577d8857c9 introduces objects in
the metadata service.

As metadata service is supposed to be using the
conductor service for it's database access, we also need to set
nova.objects.baseNovaObject.indirection_api global to point to the
conductor API so that the object actions will be done by RPC to
conductor.

Change-Id: I7aae92c0074e72841aa6c654ad0ada25045863b1
Closes-bug: #1268665
VMware: upload images to temporary directory

The patch ensures that new images are uploaded to a defined
temporary directory instead of directly to the cache directory.

The reasons for this are as follows:
1. More than one nova-compute may try and upload the same image
to the datastore at the same time
2. If there are errors then the temporary folder can be purged
3. When the image is downloaded it will be moved to the cache
directory. Only once an image has been successfully downloaded
will it be moved. This will help with false positives with
cache image deletion

The first phase of blueprint vmware-image-cache-management.

Change-Id: I4f3ee90ae866583e8df782ff89d2b11bbebf9c39
Merge "Set objects indirection API in metadata service"
Merge "VMware: upload images to temporary directory"