Remove the expressions module, it will be folded into operators
Add the initialize phase back to Object. It complements 'destroy'
simplify Decalarative and DeclarativeProperty.
Move the expression classes into operators. This makes more sense.
Finish the refactor of the Messener class to use Atom.
Refactor Templated and friends to use Atom
Add the standard inverter and tracer as independent modules.
Refactor Widget and Window to use Atom
Update the descriptions class attribute
update the descriptions class attribute
Fix looper typos
Add convenience methods to Messenger.
Use events instead of signals
Allow tracing Atom instances and listening to Atom events.
Port Session to use Atom
Port a bunch of widgets to Atom