cyclades: Bug fixes in volume related commands

* Add a check to both name length and disk template length in
snf-manage volume-type-create.
* Add a check for the metadata length of snapshots.
* Add a generic try/except clause to handle Pithos responses.
* Add --user/--public options in snapshot-show/image-show.
* Add a boolean "snapshot" field in image-list.
* Remove unused user agrument from backend.get_snapshot().
* Remove --wait option from snapshot-create.
* Various typo fixes.
Eliminate non-ASCII char from settings and NEWS

Closes #131
astakos: Update tests

fix project application form submit tests
astakos: Remove debug statement
Merge branch 'feature-ui-improvements' of https://github.com/vinilios/synnefo into develop
astakos: Fix typo in setting name
astakos: Invalidate user object before updating last login date

to ensure user object modifications that took place during the
login request, such as updated token expiration date, won't
get overridden.
astakos: Filter out surplus projects in usage view

do not display projects the user is not member to and no resources
are consumed from the available project quotas.
astakos: Return tuple in silent mode

Fix `check_conflicting_projects` function in order to return a (result,
message) tuple in silent mode, which is expected by
`validate_project_action` function.
astakos: Add cyclades_volume in service script

Add the missing cyclades_volume definition in the service registration
script.
pithos: Retrieve XSEG segment type and name
pithos: Refactor Gunicorn conf file
pithos: Add Archipelago conf file to params
pithos: Refactor Archipelago options parsing
pithos: Use Archipelago mapper for storing mapfile
pithos: Remove mapfile hexlification functionality

Until now Pithos was using unhexlified mapfiles but now
Archipelago transparently converts those mapfiles
to hexlified.
Mapper functions do not need to convert unhexlified mapfiles
to hexlified ones.
pithos: Differentiate object hashmap from mapfile

Object mapfiles on the storage backend will no more be identified by the
object's hashmap (content depended).
Each object upon creation will be assigned with a unique tag by which they
will be referenced on the storage backend.
This commit contains the necessary modifications in the pithos database.
pithos: Handle properly zero size objects

The backend should not store zero size objects.
This commit contains the necessary modifications for the modular backend.
pithos: Fix copy operation

Newly created objects via copy will be associated with a new mapfile.
Hence, the copy operation should store this mapfile to the storage
backend.
pithos: Extend column list