Crash Reporting

We now use a per-athlete setting to track if the last
time the athlete was opened GC shutdown gracefully.

If it didn't then we show a dialog box with some basic
data to use to debug / diag the problem. For now it is
just limited to;

* metric.log
* athlete directory listing (by modified time)
* app settings

We explicitly DO NOT include personal information such
as DOB, Weight, Sex nor critical information such as userids
or passwords.

This is a first stab at this, and we will almost certainly
improve it to include other .xml config files as well as
automatically posting an email (or similar).

Fixes #596.