bitbake: Add start of bitbake regression/self testing

This adds some basic unit testing for the codeparser and data store code. Many of
the actual test cases were taken from work by Chris Larson's OE-Signatures work but with
changes to adapt to the current bitbake APIs we need to test.

I also imported CoW tests written by Holger Freyther from the original bitbake-test
codebase: http://svn.berlios.de/wsvn/bitbake/trunk/bitbake-tests/tests/ and
some tests from the doctests that were removed in commit:
http://git.openembedded.org/bitbake/commit?id=3a11c2807972bbbddffde2fa67fc380d159da467

(Bitbake rev: ae4a95780e3e08cf73c854efa8cd93379e00c4e5)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake-selftest

@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2012 Richard Purdie
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import os
+import sys, logging
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.dirname(__file__)), 'lib'))
+
+import unittest
+try:
+    import bb
+except RuntimeError as exc:
+    sys.exit(str(exc))
+
+tests = ["bb.tests.codeparser", 
+         "bb.tests.cow",
+         "bb.tests.data",
+         "bb.tests.fetch",
+         "bb.tests.utils"]
+
+for t in tests:
+    __import__(t)
+
+unittest.main(argv=["bitbake-selftest"] + tests)
+