cyclades: Check that volume type ID is an int

Make `flavor-create` command to check that the given volume type ID is
an integer.
pithos: Set v0 size on Archipelago request
cyclades: Update vncauthproxy requirement

Require vncauthproxy>1.5.
docs: Update docs for 0.16
Add archipelago to Pithos backend dependencies
Merge pull request #214 from cnanakos/release-0.16

Update docs and fix Pithos Archipelago request
Add NEWS for Synnefo 0.16rc1
docs: Update 0.16 upgrade guide
docs: Link v0.16 Chaneglog and NEWS in admin guide
astakos: Fix percentage bar bug in Usage tab
astakos: Wrong module names in MESSAGES_VIEWS_MAP

During the patch 'astakos: reorganize views' the module 'im/views.py'
was transformed into a directory and the code was moved to
'im/views/im.py'. Fix the wrong module names in MESSAGES_VIEWS_MAP
dictionary so that ASTAKOS_*_MESSAGES will be displayed.
branding: BRANDING_FONTS_CSS_URLS not defined

Define the 'BRANDING_FONTS_CSS_URLS' parameter in the config file.