Release 1.9.1

Fixed:
- Fresh installs no longer fail: bundled modeler_api circular-reference
  patch (#3592728) and removed stale eca_modeller_bpmn from the core
  recipe (#3592734); Drush works again on fresh installs.
- Book navigation sidebar is populated after demo content import
  (#3570119); new drush openintranet:import-book-structure command.
- Block quote styling no longer affects the footer copyright (#3532305).

Updated:
- Field Group 4.0 and Flag 5.0.3 (previously unsupported releases).

Improved:
- User account edit form styling (#3592730).
- Local task edit links rendered near the content on node and user
  pages (#3592733).
- Block quotes highlighted in rich-text content (#3532305).