Consider logging exceptions caught by `LoadSupport`

[ghsolomon]

LoadSupport.doLoadAsync catches exceptions thrown by HoistModel.doLoadAsync and updates its lastLoadException observable accordingly. It also includes the exception in the browser console log, at an appropriate log-level. However, it does not log these exceptions on the server.

Consider logging exceptions not marked as routine and not thrown on autoRefresh to the server so they are reported.

Alternatively, app developers should be encouraged to catch and handle exceptions themselves, but our current story is that LoadSupport will only know about uncaught exceptions (or exceptions that are caught, handled, and rethrown).