Make sequences publishable. Extract publishable module.

User was modified, to add cancan methods for use outside controller.
Filtering logic in models/collection_filter.rb

Also separate collections for @community_activities and @official_activities
whitespace fix only.
Add 'Show Mine' list next to activities.

[#55992844]
Add 'Show Mine' list next to sequences, & home pages.

[#55992844]
Clean up whitespace.
Sequence: add publication_status, and is_offical for activity parity.
Merge branch 'master' into staging

* master:
  Sequence: add publication_status, and is_offical for activity parity.
  Clean up whitespace.
  Add 'Show Mine' list next to sequences, & home pages.
  Add 'Show Mine' list next to activities.
  whitespace fix only.
  Filtering logic in models/collection_filter.rb
  Make sequences publishable. Extract publishable module.