Improve Hello World package to have richer elements.

[cliffano]

Hello world page currently only contains a single page with a piece of text to modify.
We need to add more assets like an image, css, or javascript, and improve the hello world page to be more interesting to show.
An idea that was discussed in the past is to have a dummy business microsite, e.g. Cafe Hello World, with 1-2 pages containing some advertising blurbs, opening hours, and perhaps contact details + embedded google maps location.

This improvement will also allow aem-test-suite to have more checks, e.g. checking the existence of items under /etc/designs/ , checking stylesheet, etc.

[priya-cr]

Updated the hello-world package to have rich components with Cafe site as sample.
This package contains editable templates and author-able components compatible with touch UI