APY-114: Update Superdesk plugins for distribution-manager

updated __init__ files, moved language plugin to core plugins
APY-114: Update Superdesk plugins for distribution-manager
APY-47: Refactor CDM to include content metadata and make it extensible

updated plugins information, fixed dependencies
removed getTimestamp usage due to CDM metadata modifications
APY-114: Update Superdesk plugins for distribution-manager

information updated and published plugins to pypi
media-archive plugin updated to not use getTimestamp
Merge pull request #503 from cristidomsa/apy-8-implement-x-filter

APY-114: Refactor CDM to include content metadata and make it extensible