Move initService() call to just before Task Creation

This makes a little bit more sense than in the constructor.

If we put this in the constructor, then initService() is called even
before action-oriented command line options  have been called
(E.g., --tasks (list) or --install)
Some initialization refactoring

- Refactor local task resolution into a separate classmethod,
`resolveDependencies`
- Move runit-install and task list option handlers into a separate
method, `preprocessOptions`.  This is now before `createTasks()`
in the initialization flow.
- Simplify `createTasks()` to only handle task creation logic