Bump version to 0.16rc3
burnin: Extend snapshots tests

Provide tests for spawning a VM from a snapshot.
burnin: Cleanup stale snapshots
burnin: Don't check snapshots' metadata

Function '_get_list_of_sys_images' should not return registered
snapshots.
cyclades: Use X-UA-Compatible meta tag

Using this tag we explicitly set the Compatibility mode for Internet
Explorer to 'Standard'.
admin: Return QuerySet when a filter has no input

If a filter has not been given an input, then django-filter should
normally not call its function. However, it seems this is not the case
with the index Volume filter, whose function is called with no value and
as a result, it returns an empty QuerySet.

Fix this issue by checking in filter_index if it has been passed with
any parameters. Also, since this issue may appear in other filter
functions too, add the same check in every function that doesn't have
it.

NOTE: Model filters have a decorator that automatically does this check
for them.
pithos: Extend backend

Provide an additional backend method 'get_object_by_uuid'
which gets the object's UUID as an input
and return metadata and permission information
about the object.
pithos: PEP8 fixes
pithos: Slight change in get_domain_objects

This method gets two keyword arguments: user and check_permissions.
If check_permissions is True returns only the object accessible to the user.
Otherwise list all the objects for the specific domain ignoring
permissions.
The latter case is only meaningful if user is not provided,
therefore in that case it raises AssertionError.
astakos: Add email notifications recipients

Astakos accepts three lists of people who receive application
notifications, namely 'ADMINS', 'HELPDESK' and 'MANAGERS'. Then it sends
email notifications in a preconfigured way in these lists (ie. project
creation notifications are always sent to the 'HELPDESK' and 'MANAGERS'
email lists).

We would like to enable Astakos to specify explicitly the lists in which
every notification will be sent. This commit adds the corresponding
settings that will enable this feature.

For convenience, Astakos groups the notifications in three categories
and let the user define the recipients for these.
  - ACCOUNT_NOTIFICATIONS_RECIPIENTS receive notifications for 'account
    pending moderation' and 'account activated' actions.
  - FEEDBACK_NOTIFICATIONS_RECIPIENTS receive feedback notifications
  - PROJECT_NOTIFICATIONS_RECIPIENTS receive notifications for 'project
    creations' and 'project modification' actions.

Furthermore, one can explicitly specify the recipients for a specific
notification by using one of the following settings:
  - ACCOUNT_PENDING_MODERATION_RECIPIENTS
  - ACCOUNT_ACTIVATED_RECIPIENTS
  - PROJECT_CREATION_RECIPIENTS
  - PROJECT_MODIFICATION_RECIPIENTS
By default, these settings are not exposed to the config file.
astakos: Sent notifications to the specified lists

Use *_RECIPIENTS settings and sent email notifications to the
appropriate lists.
astakos: Document usage of '*_RECIPIENTS' settings

Document the usage of '*_RECIPIENTS' settings in Astakos to control the
lists were Astakos sends notifications. These lists used to be
preconfigured.
gtools: Fix a race in the cpustats collectd plugin

If the VM has just been started, the cpustats collectd plugin might try
to read /proc/<pid>/fd/ for VCPUs fds, before qemu has initialized /
created the VCPUs. This led to a ZeroDivision error in the collectd
plugin. Make sure to skip that particular VM until the VCPUs have been
created.
cyclades: Catch corner case in reconciliation

Include 'ERROR' in the states for which we check if the NIC exists in
the Ganeti instance.
ci: Update flavor option for burnin

Do not use only file disk templates, since an archipelago disk template
is required for snapshot tests.
cyclades: Add snapshot property in lowercase

Snapshot properties are stored in lowercase in Pithos DB. It is the
image/plaknton API that converts them to uppercase.
cyclades: Get Pithos objects by their UUID

Use the newly introduced 'get_object_by_uuid' method to get a Pithos
object by its UUID, instead of mapping a UUID to a (account, container,
name) tuple.

Also, remove the '--user' and '--public' options from 'image-show' and
'snapshot-show' management commands. Instead, use the
'check_permissions' option to bypass Pithos permission check.

Finally, fix plankton tests to mock the 'get_object_by_uuid' method.
docs: Update debian install guide
docs: Update upgrade release-0.16 guide
pithos: Add umask option on gunicorn conf file