bitbake: toaster: add toaster code to bitbake

bitbake: toaster: add toaster code to bitbake

This patch adds the Toaster component to Bitbake.

Toaster is a module designed to record the progress of a
Bitbake build, and data about the resultant artifacts.

It contains a web-based interface and a REST API allowing
post-facto inspection of the build process and artifacts.

Features present in this build:
* toaster start script
* relational data model
* Django boilerplate code
* the REST API
* the Simple UI web interface

This patch has all the development history squashed together.

Code portions contributed by Calin Dragomir <calindragomir@gmail.com>.

(Bitbake rev: d24334a5e83d09b3ab227af485971bb768bf5412)

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