iso date formats were breaking the SVG images in firefox. changed date format to a known working format.
fixes #409
bug fixes, image previews for pdf's and failed uploads
Merge branch 'develop' of github.com:harvard-lil/perma into develop
Clean up link dragging.

Fixes #406 and #407
fixed single-linky header issue
Merge branch 'develop' of github.com:harvard-lil/perma into develop
Add contingency plan page.

This adds a contingency plan page, linked from the FAQ for “will you
save my link forever?”.

This also does some cleanup for static pages:
- Check logged-in status via request.user variable accessible in every
template.
- Use generic template view for templates that don’t need special setup.
draggable stuff
Merge branch 'dev.contingency' of https://github.com/jcushman/perma into jcushman-dev.contingency

Conflicts:
	perma_web/perma/templates/single-link.html
Merge branch 'develop' into jcushman-dev.contingency
Let clicks pass through the watermark in the source view.
Add search and persistent pagination to user/registrar/vesting-org pages.

Fixes #403 and #358.
Use django send_mail function.

We were using raw smtplib in email_new_user, which doesn’t respect
Django’s email config. This seems to work on my dev, but should be
tested on staging.
Show link creation time in user's timezone.
Handle link creation dates in backend.
We were downloading the entire contents of PDFs when we were trying to get their titles (which would always fail since we only look for titles as they'd appear in an html or xml doc). now, we get the first MB and if it's more than that, we just use the url as the title of the archive (and in the case of a PDF, pass off the PDF to the PDF downloading task).

This fixes #353 since that pdf was large and we were super slow when trying to get the title (I'm guessing the user game up and throught we weren't indexing it.

we need to revisit our entire flow for finding mime type/determinging file type of url. it's a sloppy now.
pdf status was not working. fixed. fixes #335
closes #430
Revert "closes #430"

This reverts commit d0e75fbe531daf3d975986baa1b7bd9d53d7833b.
closes #432