adding the console-runtest helper as discussed on py-dev

--HG--
branch : trunk

contrib/runtesthelper.py

@@ -0,0 +1,19 @@
+"""
+this little helper allows to run tests multiple times
+in the same process.  useful for running tests from 
+a console.
+"""
+import py, sys
+
+def pytest(argv=None):
+    if argv is None:
+        argv = []
+    try:
+        sys.argv[1:] = argv
+        py.cmdline.pytest()
+    except SystemExit:
+        pass
+    # we need to reset the global py.test.config object
+    py._com.comregistry = py._com.comregistry.__class__([])
+    py.test.config = py.test.config.__class__(
+        pluginmanager=py.test._PluginManager(py._com.comregistry))