Summary:
This draws from our hgwatchman client code to provide a simple
watchman client API for python code.
This changes the makefile so that we install our watchman python module
during `make install`. It also wires up a rudimentary test of the
client that talks to one of the instances set up by
WatchmanIntegrationEngine.
Test Plan: `./configure --with-python ; make integration`
Reviewers: sid0, achao
Reviewed By: sid0
Subscribers: moshez
Differential Revision: https://phabricator.fb.com/D1323720
