Make settings listener thread a non-daemon thread.

Daemon threads don't exist in Python <= 3.2; fortunately, we don't
really need them.
Require Python >= 3.3.

For consistency, also convert existing checks to use asserts.
Bumps wpull>=0.33 pipeline requirements.
Updates INSTALL file with latest info for wpull.

Closes ArchiveTeam/ArchiveBot#58.
settings.ignore_url_p needs to return a string.

Previously, it returned a compiled RE object.  However, before *that*,
we returned a string.

The interface for this method hasn't really ever been hammered down, but
when that happens, sometimes the best thing to do is to defer to
tradition.
Sleep with wpull's wait_time hook.  #62.

What a charmer.
Eliminate !reqd.  #62.

Differentiating between page requisites and non-requisites using wpull's
new sleep time hook is a bit tricky -- or, at least, I can't see any
clean way to do it.

Fortunately, it doesn't really matter.
Bump pipeline version.
Point RSS/Atom profile image to an image on archiveteam.org.

Closes #51.
Use Trollop for job option parsing; add --js.
Pipeline and bot support for wpull's PhantomJS mode.
Don't generate page snapshots in PhantomJS mode.
--js -> --phantomjs.

The latter is longer, but seems to be more obvious.