Code review comment for lp:~bcsaller/pyjuju/lxc-omega

There's still no information on how to review this branch without looking at
changes already reviewed in previous branches.

Please do mention what are the pre-requisite branches in the summary, when it
contains multiple branches.

One detail I could already figure on it:

[1]

+@contextlib.contextmanager
+def lock_manager(path):
+ """Use a file to represent a lock.
(...)
+ # This will raise if the file exists
+ fd = os.open(path, os.O_CREAT | os.O_RDWR | os.O_EXCL)

Please use the existing filesystem lock in Twisted. This version
will explode badly when the second process tries to get into the
mutex region.