* Allow the following predefined analyses :
undefined_function_calls, undefined_functions, locals_not_used,
exports_not_used, deprecated_function_calls, deprecated_functions
* Trap some possible errors in case module information is not
available
* ignore_xref works on all checks and can take {M,F,A} tuples.
(Automatic behaviour export suppression still only works on
exports_not_used)
