Add bower, sass. Beginning admin page example.

Bower is now used to install AngularJS and AngularResource. Sass has a
simple SCSS file for example compilation.

Bower will install its packages to the webapp/bower_components
directory.

All files in the webapp/styles directory will be compiled into CSS. The
compilation is recursive. The compiled CSS files are placed in the same
location as the source.

Started a simple building block configuration page example that uses all
the major components: Jersey, Angular, Sass. Just to have an example
working application.

Also thoroughly document bb-manifest.xml, hopefully, we can provide
commented out blocks to demostrate how to create modules, course tools,
etc using the manifest.