Wrap most long lines: fix all bad hanging indents.

* Fixes many E501-s; more work needs to be done.
* Fixes all E127-s.
Enable flake8 style check for hanging indents.
Bump flake8 version.
Merge pull request #559 from Renelvon/wrap_long_lines_1

Style fixes: wrap long lines, fix hanging indents, bump flake8