Describe the bug
ut_junit_reporter can produce invalid output on failing tests with long failure message.

The error that we see in import of test results in Jenkins is:

Failed to read test report file [...snap...]/test_results.xml
org.dom4j.DocumentException: Error on line 6527 of document  : The reference to entity "lt" must end with the ';' delimiter. Nested exception: The reference to entity "lt" must end with the ';' delimiter.

Provide version info
Running on latest utPLSQL v3.1.6

Information about client software
Not relevant

To Reproduce
Have a test that is failing and produces more than 4000 chars of output data and be unlucky enough to get the < string at 4000 chars so the reporter inserts a line break.

Example:

   ... <INSERT_TMSTMP>2018-07-28T01:01:37.092127</INSERT_TMSTMP>&lt
;GROUP_ID/>...

Expected behavior
We should probably make the failure message as CDATA rather than escape the chars.