Print all log messages from FMUs

[kyllingstad]

Messages logged by FMU code with severity fmiError or fmiFatal are not forwarded to the console by coralslave, on the presumption that such a logging operation will be followed by an FMI function call failure of the same severity. This is not necessarily the case, so all such messages should be printed.

[kyllingstad]

Adding "conformance" label, as FMI does not require that a logged fmiError be followed by an fmiError return value.