New features

Main changes are:

- New logging feature which follows PSR-3. Has its own Abstract class and Interface, and provides the ability to output particular levels of log output based on your situation. You can also set options for the operation itself -- allowing us the ability to send logging to an external service (in future).

- Changes to persistent object. Mainly separating the service/parent objects for greater clarity.

- Fix to Server class so that new server objects cannot be attached to networks without valid UUIDs. In response to 500 errors I was getting earlier.