Fixed #835 - required updating the schema for the comment table to include the profile image url, also changed logic for retrieving & displaying the post title for a comment so that the title from the post is stored with the comment if it doesn't already have one
Corrected db upgrade logic so that comment table isn't reset twice
getPhotonImageUrl() now returns an empty string when an empty url is passed (previously threw an exception)
Merge pull request #840 from wordpress-mobile/issue/835-gravatar-difference

Issue/835 gravatar difference