Add text for Ask-HN above comments

This is at least part of what is requested in #6.  This PR also adds some nice things like a loading view which can be easily added to any list as an empty view so that "loading" is displayed instead of a blank screen.

Screenshots:
Loading screen on the comments page: http://tinypic.com/r/2hqfog3/5
Some text with links: http://tinypic.com/r/517gom/5
Bottom margin: http://tinypic.com/r/2wmhvmv/5
Comment that doesn't take up the whole screen: http://tinypic.com/r/2ll0o5d/5
Loading panel on the comments page: http://tinypic.com/r/2hqfog3/5
Loading panel on the home screen: http://tinypic.com/r/n3uc6e/5