Ignore some JavaScript cruft that always 404s
Ignore tumblr.com/share/link/
Ignore stumbleupon.com/badge/embed/
Ignore /%5C%5C%22 and similar
Ignore %5C%27 as well
Ignore /%5C/%5C/
Ignore more myspace /PostTo/
Remove --ascii-print.  #49.

This may fix the \u2018 / \u2019 escapes that we're seeing in the
dashboard.

--ascii-print was added for Python 2 compatibility, but ArchiveBot's
pipeline is now all Python 3.
Bot-level changes to support custom UAs.  #85.
Pipeline changes for custom UAs.  #85.
Generalize IgnorePatternUpdater.  #85.

We'll use this as the basis for other CouchDB updaters, i.e. the
user-agent updater.
Update user agents from cogs.  #85.