Fixed disqus images not showing bug.

The combination of overflow:auto and bottom:0 in .snap-content was
causing disqus avatars/images to not show.
I removed bottom:0.  That caused the .snap-drawer div to scroll
with the page, so I changed it's position attribute from absolute
to fixed.
Merge pull request #32 from mojotech/cg/fix_disqus_image_problem

Fixed disqus images not showing bug.  The combination of overflow:auto a...