dillon1000/react

Host environment side-effects

This creates a new API for processing side-effects on the host
environment.

During initial reconciliation host instances are created during
the time sliced periods.

During updates there is an opportunity for the host
to prepare something on the instance during the time slicing, and
to determine whether there were any changes. The could be thrown
away.

At the commit phase, these changes are finally committed to the
host instance.