IllegalStateException broke report every time

[xsmrcek]

AbstractXmlReporterExtension.printString() method is called by every print method of report extensions and can throw IllegalStateException. It seems that if this exception is thrown anywhere report is going to be broken.

[paveljandejsek]

First solution might be to use some buffered stream that would not get flushed when such exception occurs (ie. instead of invalid report there would be no report at all)

Second phase in the future might be to deal somehow with closing opened tags and generate valid report everytime.