Enable PEP8 checks E128, E251 and E265

* E128 continuation line under-indented for visual indent
* E251 unexpected spaces around keyword / parameter equals
* E265 block comment should start with '# '

Change-Id: Ie4b7d8a392c8e8bed58c171b5fc1b9db308036bc
Merge "Enable PEP8 checks E128, E251 and E265"