Build script now generates one build folder per family

The "build.sh" script now generates:
  build/phone/
  build/tablet/
  build/desktop/
  build/tv/
  build/samsungtv/

Optimized entry points in the "app" folder do not work anymore: they
will be copied over to the appropriate "build" folder (as index.html)
where they will find the appropriate JavaScript.

The ".optimized.js" files do not appear in the "app" folder anymore.

Using one version per family has a drawback: if a build includes more
than one family of devices, the resulting package will contain images
more than once. It is not such a big deal as far as Sleek is
concerned, because most of the files (CSS and images included) are
on per device family basis.
Template built. v1.6.0

No actual change in the code but build versions now sit in separate
"build/" folders so that the Factory may only include the code that
it really needs for a given deploy.