Avoid re-creating Nova home directory when not in usegitrepo mode

This is always bound to conflict with the packages, and we're
fine with having any home directory being created. The one
configured by the packages should be the correct one.

This also simplifies the code a little.
Merge pull request #282 from dirkmueller/ssh_cleanup

Avoid re-creating Nova home directory when not in usegitrepo mode
Update api-paste.ini

Enable V3 API Route
Fix keystone signing dir
Fix a few oversights in nova.conf.erb merging
Merge pull request #287 from dirkmueller/nova_conf_update

Nova conf update
Use new validation API in validate_proposal_after_save
Use new find_dep_proposal helper
Merge pull request #291 from vuntz/validation

Use new helpers to create/validate proposals
Add support for vmwareapi.VMwareVCDriver with dynamic tables