exception handler that logs exceptions to log files

[htgoebel]

From ​http://groups.google.com/group/pyinstaller/browse_thread/thread/7ba7b9efad7feb01

The only way to implement such a feature is to install an exception handler in Python. I think it's a feature that could make sense for PyInstaller?: when console is disabled, an exception handler should be installed that logs exceptions to log files and/or display a message box using the OS native GUI support, possibly through a different process not to create weird interactions with any running GUI in the user's application.

Obviously this would be a debug feature that can be disabled if not needed.

[matysek]

When in debug mode we could also redirect the debug output from iu.py to this file or message box. The debug output from iu.py is disabled by default.