dillon1000/react

Remove tryComponentDidMount/Update in favor of commit phase try block

We still need tryComponentWillUnmount because deletion should be non-
interruptible.

Refactoring the commit phase to better handle errors also allows us
to switch between fast and slow versions of the work loop. The slower
version runs whenever there are captured errors; it must check each
unit of work to see if it has failed. The faster version runs in the
normal case where there are no errors. Whenever an error is thrown, we
switch from the fast work loop to the slow work loop.