Create a deprecated Open Social package

• Create a deprecated Open Social package
• Make Social Collab dependent of this gadget
• Rename nuxeo-admin-center-oauth-opensocial in nuxeo-admin-center-oauth
• Move opensocial contribs from nuxeo-admin-center-oauth to nuxeo-opensocial-gadgets
• move activityCharts.xhtml and tabs actions from nuxeo-admin-center to nuxeo-opensocial-gadgets
• Make Nuxeo Polls, Nuxeo Agenda and Nuxeo RSS reader optional (and create tickets for update them (polls and agenda)
• Explorer: remove the contributed gadgets (to validate with Thierry Delprat)

package name : nuxeo-opensocial
repo name : marketplace-opensocial
bundles :
nuxeo-opensocial-gadgets
nuxeo-admin-center-oauth-opensocial
nuxeo-opensocial-server
nuxeo-opensocial-features
nuxeo-opensocial-gadgets-core
nuxeo-opensocial-container
nuxeo-opensocial-container-webapp
nuxeo-opensocial-spaces
nuxeo-user-dashboard-opensocial
nuxeo-webengine-gadgets