Use American English for "behavior" in docs.

Prompted by plaes on #pocoo, mitsuhiko confirmed to use American English.

docs/design.rst

@@ -48,7 +48,7 @@ allocated will be freed again.
 
 Another thing that becomes possible when you have an explicit object lying
 around in your code is that you can subclass the base class
-(:class:`~flask.Flask`) to alter specific behaviour.  This would not be
+(:class:`~flask.Flask`) to alter specific behavior.  This would not be
 possible without hacks if the object were created ahead of time for you
 based on a class that is not exposed to you.
 

docs/extensiondev.rst

@@ -40,7 +40,7 @@ that it works with multiple Flask application instances at once.  This is
 a requirement because many people will use patterns like the
 :ref:`app-factories` pattern to create their application as needed to aid
 unittests and to support multiple configurations.  Because of that it is
-crucial that your application supports that kind of behaviour.
+crucial that your application supports that kind of behavior.
 
 Most importantly the extension must be shipped with a `setup.py` file and
 registered on PyPI.  Also the development checkout link should work so
@@ -145,7 +145,7 @@ initialization functions:
 classes:
 
     Classes work mostly like initialization functions but can later be
-    used to further change the behaviour.  For an example look at how the
+    used to further change the behavior.  For an example look at how the
     `OAuth extension`_ works: there is an `OAuth` object that provides
     some helper functions like `OAuth.remote_app` to create a reference to
     a remote application that uses OAuth.

docs/htmlfaq.rst

@@ -52,7 +52,7 @@ Development of the HTML5 specification was started in 2004 under the name
 "Web Applications 1.0" by the Web Hypertext Application Technology Working
 Group, or WHATWG (which was formed by the major browser vendors Apple,
 Mozilla, and Opera) with the goal of writing a new and improved HTML
-specification, based on existing browser behaviour instead of unrealistic
+specification, based on existing browser behavior instead of unrealistic
 and backwards-incompatible specifications.
 
 For example, in HTML4 ``<title/Hello/`` theoretically parses exactly the

docs/patterns/jquery.rst

@@ -153,7 +153,7 @@ explanation of the little bit of code above:
 2. ``$('selector')`` selects an element and lets you operate on it.
 3. ``element.bind('event', func)`` specifies a function that should run
    when the user clicked on the element.  If that function returns
-   `false`, the default behaviour will not kick in (in this case, navigate
+   `false`, the default behavior will not kick in (in this case, navigate
    to the `#` URL).
 4. ``$.getJSON(url, data, func)`` sends a `GET` request to `url` and will
    send the contents of the `data` object as query parameters.  Once the

docs/patterns/mongokit.rst

@@ -17,7 +17,7 @@ here:
 Declarative
 -----------
 
-The default behaviour of MongoKit is the declarative one that is based on
+The default behavior of MongoKit is the declarative one that is based on
 common ideas from Django or the SQLAlchemy declarative extension.
 
 Here an example `app.py` module for your application::

docs/quickstart.rst

@@ -166,7 +166,7 @@ The following converters exist:
 `path`      like the default but also accepts slashes
 =========== ===========================================
 
-.. admonition:: Unique URLs / Redirection Behaviour
+.. admonition:: Unique URLs / Redirection Behavior
 
    Flask's URL rules are based on Werkzeug's routing module.  The idea
    behind that module is to ensure beautiful and unique URLs based on

docs/templating.rst

@@ -63,7 +63,7 @@ by default:
 
    The :func:`flask.get_flashed_messages` function.
 
-.. admonition:: The Jinja Context Behaviour
+.. admonition:: The Jinja Context Behavior
 
    These variables are added to the context of variables, they are not
    global variables.  The difference is that by default these will not