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
bug fix: a couple of lines handn't been updated to use the request insetad of the the old user (that we were passing from the view). updated.
Merge branch 'develop' of github.com:harvard-lil/perma into develop
closes #430
closes #431
Added meta element to tell google and bing and other crawlers to not index perma.cc archive pages.

We might want to investigate a robots.txt approach in the future too. the way we create our archive urls (perma.cc/idid-idid) is not a great fit for robots.txt. There is no pattern matching and no dissalow all, but allow about/landing/faq approach in the robots.txt spec. Google/Bing do have allow statements, but these is crawler specific.

fixes #366
Merge branch 'develop' of github.com:harvard-lil/perma into develop
Merge branch 'dev.local_date_2' of https://github.com/jcushman/perma into jcushman-dev.local_date_2
Merge branch 'dev.email' of https://github.com/jcushman/perma into jcushman-dev.email
Merge branch 'dev.sort' of https://github.com/jcushman/perma into jcushman-dev.sort

Conflicts:
	perma_web/perma/templates/user_management/manage_registrars.html
	perma_web/perma/templates/user_management/manage_users.html
	perma_web/perma/templates/user_management/manage_vesting_orgs.html
Merge branch 'dev.pointer_events' of https://github.com/jcushman/perma into jcushman-dev.pointer_events