Migrate Services (Traders) and Community Groups into new Organisation content type

[djwesto]

This is a placeholder where we can discuss the big merge of Traders with Groups. The current features we know are needed in an enhanced 'Groups' feature include:

• Customisable [sub-]menu structure
• Admins can author static pages in a hierarchical Drupal 'Book' structure
• Private Groups (All groups are visible but the content of Private groups is hidden from non-members)
• Group events
• Group news articles