Some really poor error reporting in xmlrpc auth (could easily be improved)

[Howard Miller]

The form validation for the xmlrpc form, by default, just gives the completely useless error message - "An unknown error occurred while processing this form". As this is an area where errors can easily occur this sort of message should be improved. Even if you just dump the contents of the exception object there is a whole host of useful information but this error handling doesn't report or log even the basic error message.