mail/.notmuch/hooks/post-new: Tag SWC's new site and bc repositories

Greg spun these off as replacements for the olders website and
boot-camps repositories.  There's not much development in the old
repositories now, but it doesn't hurt to keep them in our tag list.
mail/.notmuch/hooks/post-new: Tag icalendar messages
.config/rss2email.cfg: Fix 'carreers' -> 'careers' typo
mail/.notmuch/hooks/post-new: Tag Persona messages
mail/.notmuch/hooks/post-new: Tag dj-static messages
mail/.notmuch/hooks/post-new: Tag messages from planet@gentoo.org

The planet sets its own from address, and I haven't enabled force-from
for any feed in my rss2email config.
mail/.notmuch/hooks/post-new: Tag git-scm.com messages
mail/.notmuch/hooks/post-new: Tag catalyst autobuild messages
mail/.notmuch/hooks/post-new: Tag xkcd's What If? and Dilbert
mail/.notmuch/hooks/post-new: More identifiers for swc tags

Also tag RMG-Py messages with 'mentor'.
mail/.notmuch/hooks/post-new: Tag job messages

This is missing stuff from Python's job feed, but I'll extend it once
I get a new sample message from that source.
mail/.notmuch/hooks/post-new: More identifiers for journal tags

I'm not sorting everything into folder:journal anymore, so it's good
to also tag based on the sender.
mail/.notmuch/hooks/post-new: Tag news messages

The news feeds set author addresses, so I'm just using the paper name
instead of the email addresses.
mail/.notmuch/hooks/post-new: More identifiers for -inbox

I'm only occasionally interested in these messages, so don't clutter
the inbox (unless they're sent to me in particular).
.XCompose: Remove multi-0-0 sequence for the empty set

There's already an empty-set sequence in
/usr/share/X11/locale/en_US.UTF-8/Compose:

  <Multi_key> <braceleft> <braceright> : "∅"   U2205 # EMPTY SET

I'll just use that one.
.bowerrc: Opt-out of Bower's usage tracking

[1]: https://github.com/bower/bower#analytics