Annotate pylintrc w defaults and rationale

Generated from 'pylint --generate-rcfile'.

Defaults are commented out.

Exceptions to defaults include a rationale.

Note generation of 'pylintrc_reduced'.

Minor changes to code to conform w/ new config.
I also added `^unused_`.

This is in place for cases where a subclass needs to maintain a signature of a method, but doesn't use all the arguments:
```python
class Foo(Bar):
    def do_baz(self, baz1, baz2):
        foo_func(baz1)  # baz2 unused
```

In order to make the intent of `do_baz` clear, the convention is to instead define it as
```python
class Foo(Bar):
    def do_baz(self, baz1, unused_baz2):
        foo_func(baz1)
```