Story 59656310: Improved keyboard navigation for autocompletes
Sticky header partial updates:
handling more than one header at a level
expandable/collapsible headers as for PBC request filters

This is a WIP.  Sending to Andy for further review
Fixed issues with sticky headers where headers outside the viewport were used in header positioning computations (also reverted some prior changes as they resulted in regressions)
Fixed an issue where headers with a height taller than the "scrollaway margin" were disappearing early
Updated sticky headers to use the original header elements as the sticky ones (using the clones as placeholders)
Adding keyboard create fix for documents and objectives templates
Allow import of Controls to Programs.
Match program control import redirect to other redirects.
Restrict page views. Defines a new action for viewing an object page.
Further define a migration that adds the required permissions for the
different roles.
Disabled "Unmap" on the My Work page
Change Relationship to use standard polymorphic pattern

* Previously it was done differently than all the other Mapping objects.
Merge branch 'develop' into feature/restrict-page-permission
Adopt new head for migrations.
Merge pull request #574 from reciprocity/feature/fix-relationship-relationships

Change Relationship to use standard polymorphic pattern
Bump version to 16.
Merge pull request #578 from reciprocity/feature/versionToS16

Bump version to 16.
Merge pull request #573 from reciprocity/feature/disable_mywork_unmap

Disabled "Unmap" for objects on the My Work page
Merge pull request #577 from reciprocity/feature/restrict-page-permission

60433102 Object pages require proper permission to view, now.
Merge pull request #558 from reciprocity/feature/autocomplete-kb-nav

Fixed keyboard nav for autocompletes (#59656310)
Merge pull request #559 from reciprocity/feature/sticky_header_enhancements

Enhanced sticky headers to be more versatile, fixed bugs with clones