Article.setDefaults
Clean attrs before setting defaults
Start setting defaults

I'm not very happy with this for two reasons:

1) findOrCreate..  calls setGuid, which calls setDefaults, which calls
cleanAttrs.  That feels awkward.

2) I'm reinventing the validation wheel, but then again I don't want to
be too tied to sequelize, because I may very well migrate to bookshelf.

Whatever.  Done is beautiful.
Don't show html artifacts in defaulted title
Title defaults to link when missing.  Blegh.

So... The previous commit was to get rid of html elements leaking into
the subject.  I tried lodash/underscore's unescape, but that only works
for the minimal amount of escaping to avoid XSS.  That means it did not
change &nbsp; to a space.  So, I tried node-ent, but that appeared to
replace &nbsp; with a utf-8 character, which made the (commented-out)
test fail with no visible differences, so I assume it's a difference of
utf8 vs non-utf8.