Fixed HTML import into newsletter content. Have attempted to use the Premailer library here, not sure if it's overkill or wrong idea, but it does seem to do the job. Of course, it may just be getting called twice in the process.

Couple of minor link fixes in admin templates. Some cleanup of now redundant code and modules (I'm sure there's lots more of that)

Presently this is mostly operational during experimental testing. There's one issue with particularly complex html page inserts (smtp connection raises malformed start tag), but otherwise can create text or html linked newsletters and do a test sending. Need to test the mail mailer function too.