tox.ini: Added default testing of Python 2.4, + new manual env: py27-xunit-xmlcover for hudson.

.gitignore

@@ -14,3 +14,4 @@ pip-log.txt
 erl_crash.dump
 *.db
 Documentation/
+.tox/

tox.ini

@@ -1,5 +1,9 @@
 [tox]
-envlist = py26,py27
+envlist = py24,py25,py26,py27
 [testenv]
-commands=nosetests
+commands = nosetests
+
+[testenv:py27-xunit-xmlcover]
+basepython = python2.7
+commands = nosetests --with-xunit --with-coverage3 --cover3-xml