The org.nuxeo.common.utils.TestUserAgent is printing more than 700 lines of debug information to stdout:
Running org.nuxeo.common.utils.TestUserAgent Testing user agent : Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a2) (...) Testing bad user agent : Mozilla/4.0 (compatible; MSIE 6.01; Windows NT 6.0) Tests run: 4, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.045 sec - in org.nuxeo.common.utils.TestUserAgent
Use a logger with the DEBUG level to replace all occurrences of System.out.println()