Add support for debugging watches
Bump version to 0.9
Extend watch to allow displaying stats in a loop
Handle NoNodeError for tree command
Group ZK specific code under AugumentedClient plus cleanups

Start moving ZK specific code onto AugumentedClient plus cleaned
up some bits and pieces whilst doing the move.

Also, add a new shell command: du (`directory usage`) command.
Ignore emacs temp files (*~)
Move find into AugumentedClient so it can be tested
Move grep into AugumentedClient
Move tree into AugumentedClient
Moved more things around to clear the way for tests