Added filtering for PBC requests
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
Story 57174850: Changed display of evidence.  Also migrated object-file linkages for evidence to individual documents, rather that being listed in responses
tree filter controller (missing from previous commits)
evidence detail info added and edit evidence modal created
removing extra space
removed watermark checkbox from modals
watermark icon changed
mouseless navigation in modal forms
fixing mustache helper for tabindexing select tag
policy modal kind option updated
Allow Directive#kind to be `None` and set as Policy default
adding tabindex to select tags
Add very basic information for monitoring performance
Fix to preload Audit roles also (avoiding ___st4ck3d error)
Merge pull request #525 from reciprocity/feature/fix-role-loading

Fix to preload Audit roles also (avoiding ___st4ck3d error)
When on App Engine, use 'static.' subdomain for assets
Remove `print` statements
Merge pull request #526 from reciprocity/feature/basic-performance-logging

Basic performance / query logging; use `static` subdomain for assets; remove `print` statements
Restore RoleImplication _display_name method for log.