Gulp build process, bower component & E2E test infrastructure

These are prerequisites for converting font picker to a test- and CD-
friendly component.
Major changes:

- Add bower component definition
- Gulp build process that converts a static HTML into a JavaScript
string, so that references to external templates are no longer
necessary.
- Gulp E2E tasks and a example Casper.js test case (not yet complete)
- Move source files to /src folder as per convention
- Temporarily make Google Font Loader a local component - this should be
changed soon.