Stringify message return from update.

Receivers expect to see JSON, this follows those guidelines.
Use pagebeforeshow instead of pageshow.

Cleans up some unnecessary animation before the page is ready to be shown.
Revert to using internal request function.
Handle errors nicely, avoid error chains.

error.html goes "back" by default.  Handle the case when it is coming from an error html so as not to throw multiple errors in a row.
Make sure commands don't proliferate, clear them.