[REVIEW 3-6][REVIEW 3-6-0] Report uncaught exceptions with MessageBox on Windows

[Stephan Bergmann]

<http://cgit.freedesktop.org/libreoffice/core/commit/?id=fdfb7a3c4b3a89b73ab5546b9620348bc4984d8f> 
"Related fdo#51252: Report uncaught exceptions with MessageBox on 
Windows" is an attempt to get more useful information when a user is hit 
by <https://bugs.freedesktop.org/show_bug.cgi?id=51252> "LO cannot start 
(reports runtime error with Visual C++ Runtime Library)" etc. on 
Windows.  It displays a native message box containing the message of the 
uncaught UNO exception.

One easy way to test the effectiveness of this patch is to duplicate a 
LO installation's program\services\services.rdb as 
program\services\DUPLICATE.rdb.  Starting soffice.exe should then cause 
this fatal error (due to duplicate UNO service implementations).

Please review for libreoffice-3-6 and libreoffice-3-6-0.  The patch 
should be really harmless, as it should only kick in in situations where 
LibreOffice is failing completely anyway.

Thanks,
Stephan