Added activity type to unhandled AT message.
LL-844 #close Prevent timeline widget type change.

A simple solution was chosen. The type is removed for the time of entity
backing the Widget View being updated, this way the type is not being
reset. It seemed excessive to introduce a new entity type within schema
and changing Timeline to something else after loading.
Merge pull request #5 from learning-layers/integration

Integration, merge a bug fix