ui: Improve VM password overlay view

- Recovered copy functionality in firefox by using readonly
  attributed instead of disabled in password input element.
- Register password input handler to automatically select
  password input on click.
ui: Display inactive resize action indicators

in case vm is in error state
ui: Fix minimum quota handling in volume create view
ui: Enforce max volume size in volume create view
cyclades: Fix issue with storing images

The 'get_or_create' method should be used only for the 'uuid' and
'version' parameters.  Otherwise, any change of the image (e.g.
location) would cause the creation of a new image which would result in
integrity error.
cyclades: Pass the size of volume's origin

..to Archipelago, as 'origin_size' parameter.

Currently, the volume object is annotated with the size of the origin,
but this information is not stored in DB. This will have to be changed
when Synnefo supports detachable volumes.
cyclades: Fix wrong import
pithos: Improve test

Extend test for listing objects until a specific timestamp
to cover the case that an object is deleted after the provided timestamp.
pithos: PEP8 fix
pithos: Reset negative object sizes

Provide a database migration script that discovers
erroneously declared negative objects sizes and sets
them to 0.
pithos: Raise custom exception for invalid policies.

Raise 'InvalidPolicy' instead of 'ValuerError' exception
during account/container updates.
pithos: Change PithosBackendPool signature

PithosBackendPool constructor used to accept a number of keyword arguments
that it would pass them to the ModularBackend during the backend
instantiation.
Hence, this code required refactoring each time a new backend argument
was introduced.
This commit changes the PithosBackendPool to accept
a kwargs dictionary instead.
pithos: Recover 'get_domain_objects' from error case

Method 'get_domain_objects' should not fail if an object
(snapshot) is not available.
pithos: Fix sqlite backend
pithos: Several PEP8 and test fixes
pithos: Apply metadata/group limits for the resources

This commit sets a maximum metadata number per Pithos
resource as well as a maximum group number per account
and a maximum allowed number of group members.

More specifically:
* Introduces two new settings for Pithos:
* the maximum number of metadata each resource
  (account/container/object) can have,
  the maximum number of groups each account can have
  and the maximum number of members each group can have.
* Adds checks to enforce the above limits.
* Introduces the LimitExceeded exception raised by the backend
* when these limits are infringed.
* Refactors the backend implementation of the group/metadata
  update in order to reduce interaction with the database.

The affected backend methods are:
* update_account_meta
* update_container_meta
* update_object_meta
* register_object_map
* copy_object
* move_object
* update_object_hashmap
* update_account_groups

Applications, other than Pithos+, that use the Pithos backend
should put a special care on handling these situations.
plankton: Handle limit exceptions.

Pithos backend enforces limits on the number of the resource metadata.
If these limits are exceeded a Limitexceeded exception is raised.
Plankton should catch these exceptions and fail with BADREQUEST (400).