Make FeaturedByImage work in TextileArticles example.

Margins of container need adjustment, no gutter now.
Add ranking fields in articles. Used as sorting key in
adapter.getArticles( ). Add omit attribute to indicate article ids to
omit. Can be list or single id.
Keep articles sorted in cached list in TextileAdapter.
Make builder use home.txt, of no article is found through URL
parameters.
Comments and docstrings.
Add getCurrentArticleId( ) to SassBuilder
Make ArticleSideBar work
Make start with BlogResponse component.
Make FeaturedByImage work in TextileArticles example.
Add some predefined class names to constants.
Adjusting article source for testing.
Add ArticleSideBar and FeaturedByImage to