Output upgrade test results in JUnit XML format

The civicrm-upgrade-test [F1] shell script verifies that the CiviCRM upgrade logic executes without error for a range of databases. The outputs are displayed on the console.

To facilitate automated testing with Jenkins, the test script should create a JUnit XML [F2] that can be recognized by Jenkins. The XML output should include the name of each tested database, the pass/fail status, and (for failures) the drush output.

For example, one might replace the last ten lines ([F3] under "Report Status") with a PHP helper script. For example, the PHP helper script might be used like:

php create-junit-xml.php "/path/to/output" databases/db_1.sql.bz2 databases/db_2.sql.bz2 databases/db_3.sql.bz2 > junit.xml

[F1] https://github.com/civicrm/civicrm-upgrade-test
[F2] http://stackoverflow.com/questions/4922867/junit-xml-format-specification-that-hudson-supports
[F3] https://github.com/civicrm/civicrm-upgrade-test/blob/05a300c590fa21b0dc9fa33207f69c2415cc2def/civicrm-upgrade-test#L121