Use UTF-8 encoding for the captured Standard Output and Standard Error o...

...n the ErrorLogs ("Output Captured") Pages

Until now, the Output written by the started process was captured as ASCII, which is different from the default encoding used by FitNesse.

I am not sure about proper handling of the UnsupportedEncodingException, though.

There is no unit test for this. Writing one, might involve Stubbing the java.lang.Runtime.getRuntime() call or making the OutputReadingRunnable a public inner class and stubbing the InputStream. (Both probably needs some byte code manipulation library like PowerMock)