API: post_window_command does not work.

There is a new API event called `post_window_command` that is supposed to be executed after a window command. (listed here: https://www.sublimetext.com/docs/3/api_reference.html)

It does not work. I made an example class below (I also included a method called *on_post_window_command* since that seems to fit the naming scheme of the other events and thought the name in the docs might have been a typo).

When I run a window command, on the console I get **on <command_name>** showing that the on_window_command event is working but the post window command event never runs.

```python

class MaxPaneEvents(sublime_plugin.EventListener):

    def on_post_window_command(self, window, command_name, args):

        print("on_post " + command_name)

    def post_window_command(self, window, command_name, args):

        print("post " + command_name)

    def on_window_command(self, window, command_name, args):

        print("on " + command_name)