Merge pull request #3 from oerpub/ticket401

refs #401: stop putting the image url in the image/@alt.
Merge pull request #4 from oerpub/ticket416

refs #416: stop placing original final name in media/@alt
upgrade for xhtmlpremailer based on newest htmlpremailer
gdoc importer will now either download images (and use the local copies) or leave them where they be (and have google host them)
gdoc importer will now either download images (and use the local copies) or leave them where they be (and have google host them)
Merge branch 'gdocservice' into testing