Add JUnit XML reports; refactor test reporting

* Add Junit output file support
* Differentiate between an expected failure test and an error in the
test, as described in JUnit.
* In case of an error/exception during test, record and attach it to the
Test object and continue running the tests, and show it at the end
during the trial report.

Change-Id: Iedf6d912b3cce3333a187a4ac6d5c6b70fe9d5c5
diff --git a/selftest/suite_test/test_suite/test_fail.py b/selftest/suite_test/test_suite/test_fail.py
new file mode 100755
index 0000000..6880c81
--- /dev/null
+++ b/selftest/suite_test/test_suite/test_fail.py
@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+from osmo_gsm_tester.test import *
+
+print('I am %r / %r' % (suite.name(), test.name()))
+
+test.set_fail('EpicFail', 'This failure is expected')