Add flag feature to allow staff as well as each users to flag submissions.

opentech/apply/dashboard/templates/dashboard/dashboard.html

...apply/dashboard/templates/dashboard/includes/flagged.html

opentech/apply/dashboard/views.py

opentech/apply/flags/__init__.py

opentech/apply/flags/migrations/0001_initial.py

opentech/apply/flags/migrations/__init__.py

opentech/apply/flags/models.py

opentech/apply/flags/templates/flags/flags.html

opentech/apply/flags/templatetags/__init__.py

opentech/apply/flags/templatetags/flag_tags.py

opentech/apply/flags/urls.py

opentech/apply/flags/views.py

opentech/apply/funds/models/submissions.py

...s/templates/funds/applicationsubmission_admin_detail.html

...mplates/funds/applicationsubmission_community_detail.html

...y/funds/templates/funds/applicationsubmission_detail.html

...templates/funds/applicationsubmission_partner_detail.html

...emplates/funds/applicationsubmission_reviewer_detail.html

...ech/apply/funds/templates/funds/submissions_overview.html

...pply/funds/templates/funds/submissions_staff_flagged.html