bitbake: toaster: clone Simple UI as base for Toaster GUI

bitbake: toaster: clone Simple UI as base for Toaster GUI

This patch clones the Simple UI to provide the base code for
the development of the Toaster GUI. The clone takes the place
of the application that was reserved for Javascript MVC code.

The templates used for Simple UI are renamed to start with
an "simple_" to prevent name resolution conflict with the
Toaster GUI templates.

Minor changes are made to the settings.py and urls.py in the
toaster main section to account for the newly enabled application.

(Bitbake rev: e2fde84f16da017ba0d71aef6a1fa8e2b9255db4)

Signed-off-by: Alexandru DAMIAN <alexandru.damian@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>