Simplified toolbar definition

To define a toolbar's interaction widget, it is sufficient to specify the interaction
widgets full name in the toolbar definition instead of additionally referencing its
prototype.

Change-Id: I67a14bfd5319d07fdbcb1893cb443a67c4c50e42
Added parent widget reference to edit "toolbar" options

This allows moving the actual "remove" logic to the parent widgets without having to
listen to events.

Change-Id: Iafe3281b4cab19101f690d96676d2eac1d717264
Merge "Simplified toolbar definition"
Merge "Added parent widget reference to edit "toolbar" options"