Output XML uses always ISO-8859-1 character encoding

[jliuhtonen]

TextGroupXmlWriter calls the XML.save method without the encoding parameter. This causes the XML implementation to fall back to default encoding that is ISO-8859-1.

This will cause the writing of TEST-*.xml files to throw a java.nio.charset.UnmappableCharacterException if, for example, the test names contain characters that cannot be represented within ISO-8859-1 character set.

A good alternative to consider would be to choose the JVM's file encoding from system property file.encoding and provide an option to override this via configuration.