Exceptions mail notifications

This is of interest mostly for self-hosters of MyOwnDB.

Although the software powering MyOwnDB is thoroughly tested and developed in a strongly typed language limiting the risk of runtime exceptions occuring, the risk is not totally absent.

Now it is possible to configure an administrator email in the software configuration. When the server encounters an uncaught exception, i.e. an exceptional situation not handled by the software, the server administrator will be notified of it with details of server, the request causing the error, and the exception encoutered.

To be clear: this does not apply to end users of the web application.