specify action composition strategy in request

Allow the action composition strategy to be given in planning requests.
The composition strategy can affect the planning quality.
In some cases certain strategies may even result in no plans at all.
update composer widget UI

Change composer widget UI to allow specification of action composition
strategy per 8ff86b9bcf4b8c2f47b3f0a36a185fd9c7a7fbc7
refactor precursor testing

Add method to test for partial precursors.
change x-json-pointer to json-pointer

Drop the "x-" prefix per RFC 6648.
use try-with-resources statements
initial demo widgets
backup demo widgets
backup demo widgets
backup demo widgets
backup demo widgets