FLOE-160: Namespace change and directory restructure.

This pull request does,

1. Change the namespace for metadata components to gpii.metadata;
2. Re-construct directory structures to relocate the files for metadata and feedback demos;
3. Use css to implement the blank box used on the metadata landing page for "create new resource" link, rather than using an image.

http://issues.fluidproject.org/browse/FLOE-160
The tests for the pouchDBDataSource should be in a separate directory like the component is.