Implements is_command_paper? and is_act_paper? on Attachment
Publication search_index includes has_command_paper / has_act_paper
Publications can be filtered by Official Document Status

Relies on change to rummager schema: https://github.com/alphagov/rummager/commit/8bb9977f98218b686fd7320c7836c1b784bcbfac
Move command/act paper methods into Publicationesque

Leaving tests in publication_test.rb until we decide on the best way to test the edition
family tree.
Document filter remove button has cursor

also removes unwanted class from mustache template for document filter.
Merge conflict fix
Moved official doc filter type methods into DocumentFilterPresenter
Merge pull request #1046 from alphagov/command-act-paper-filter

https://www.pivotaltracker.com/story/show/42624263

Command & Act paper filter