buildbot.util.loop, new tests, buildbot.test.state

* Add a new test utility, buildbot.test.state, and document it
* move loop to buildbot.util
* new and improved tests for loop

buildbot/schedulers/manager.py

@@ -37,7 +37,7 @@
 
 from twisted.internet import defer
 from twisted.python import log
-from buildbot import loop
+from buildbot.util import loop
 from buildbot.util import defaultdict
 from buildbot.util.eventual import eventually
 

buildbot/test/state.py

@@ -0,0 +1,9 @@
+class State(object):
+    """
+    A simple class you can use to keep track of state throughout
+    a test.  Just assign whatever you want to its attributes.  Its
+    constructor provides a shortcut to setting initial values for
+    attributes
+    """
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)