fix bug 834300 - attachments from ATTACHMENT_HOST

Only serve raw attachments when requested on the ATTACHMENT_HOST as configured
in constance.
(some) pep8 cleanup
fix bug 782900 - Localize string
Merge pull request #848 from darkwing/localize-782900

fix bug 782900 - Localize string
fix bug 779499 - Implement legacy redirects
Merge pull request #849 from darkwing/legacy-redirects-779499

fix bug 779499 - Implement legacy redirects
fix bug 810362 - Add dash link
Merge pull request #850 from darkwing/dash-console-810362

fix bug 810362 - Add dash link
move from constance to settings
fix bug 834384: Include demo search terms in pagination links when needed
Merge pull request #851 from lmorchard/834384-search-terms-in-pagination

fix bug 834384: Include demo search terms in pagination links when needed
Merge pull request #847 from groovecoder/attachment-host-834300

fix bug 834300 - attachments from ATTACHMENT_HOST