When an application is registered using a string that gives the class
name (e.g. "apps.chrono.ChronoApp") when we automatically delete
the module from a couple of namespaces. This ensures the garbage
collector can do a deeper clean when the application is unregistered.
We also provide a means to directly register watch faces (e.g. to
replace the default clock).
Fixes: #214
Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
e76a4afd85