ivi-shell: add the shell plugin for In-Vehicle Infotainment system

- ivi-shell.so
- introduces ivi-shell/ivi-shell.[ch]

In-Vehicle Infotainment system traditionally manages surfaces with
global identification. A protocol, ivi_application, supports such a
feature by implementing a request, ivi_application::surface_creation
defined in ivi_application.xml.

The ivi-shell explicitly loads ivi-layout.so and a module to add
business logic like how to layout surfaces by using ivi-layout APIs.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>