Created a new (|Failure|_|) active pattern which matches both the Failure exception type defined in the OCaml core module as well as System.Exception (which is what is matched by F#'s built-in (|Failure|_|) pattern).
Ignore a test which doesn't yet work correctly on Mono; I don't know whether it's the test or the function that's broken, or both.
Reformatting of the IO_EndOfLine_Translations test to make it easier to understand while trying to fix it for Mono.