Provide connection isolation to Lisk and enable it by default in tests
Summary:
Allow Lisk to be put into process-isolated mode which establishes
only isolated connections. By default, put it into this mode when running
unit tests. Build some simple unit tests around object insertion and
updating.
NOTE: The one flaw in this is that $dao->establishConnection() still
punches through the isolation layer. I need to do an API change to fix this
though so I'm holding it for now. It will probably just rename getConnection()
to establishConnection() and then rename establishConnection() to something
scary like establishLiveExternalConnection().
Test Plan:
Ran unit tests.
Reviewed By: aran
Reviewers: aran, tuomaspelkonen, jungejason
CC: aran, epriestley
Differential Revision: 194