The `--verbose` option is only used by `flake8`, itself,` when parsing
and handling preliminary options.  After parsing and merging options
from the configuration file, there is no other behavioral impact to the
core of `flake8`.  In other words, setting `verbose = ...` in a
configuration file doesn't change the logging verbosity.

While the `FileProcessor` does expose a `verbose` attribute, obtained
from the parsed options, the verbosity of the core of `flake8` should be
consistent with how a plugin may respond to the attribute's value.

3d512ae added W503 and W504 to defaults.IGNORE, but the documentation
was never updated.  This commit updates the docs to match the code.

Signed-off-by: Kevin Locke <kevin@kevinlocke.name>

Refs #365

In order to write this documentation, we need to also add documentation
for the --max-complexity option which was heretofore undocumented.

Add --tee option to split report output stream.

The `--tee` option allows the linter report to be written to stdout, even
though it is being redirected to a file with the` --output-file` option.
This is useful if I want to store the report in a separate file for later
analysis but also be able to print the output on screen (e.g when running
in a CI environment).

See merge request !90