Improve sending of emails from handleException

[cnrudd]

When handleException logOnServer: true, and a user sends the error with a message/feedback, hoist-core ends up sending 2 emails:

1: first email sent without error content (was triggered when handleException dialog was opened)
2: second email sent without error content and without user's message/feedback (this one triggered user's hitting of Send button with a message)

This can create some confusion for support teams reading these incoming emails. They have to know to go to the App's Admin Activity Errors panel to read the error content and the user's message.