Windows: More useful AFSDumpFile exception info

Windows: More useful AFSDumpFile exception info

Modify AFSExceptionFilter to accept the __FUNCTION__ name
where the exception occurred.

Generate the trace dump file after the exception has been
handled so that it is possible to see where it happened
in the trace output.

Change-Id: Icddafc1066dd85b63d8d97c40c0f76c54d181ebe
Reviewed-on: http://gerrit.openafs.org/7308
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>