Fix/suppress most pylint and gpylint warnings

* Add missing function doc strings.
  Suppress this warning on trivial functions in *_warn_patterns.py.
* Remove unused g-importing-memeber, g-complex-comprehension.
* Suppress pylint warning on unrecognized g-* options.
* Suppress too-few-public-methods warnings on simple classes.
* Suppress too-many-arguments and missing-function-docstring in
  html_writer.py, which will be refactored later.
* Fix bad naming, long lines and line breaks, and bad quotes.

Test: compare output for build.log
Change-Id: Icdb34f014a10ec1e642c2cfe8003fc3ae245b507

tools/warn/severity.py

@@ -19,8 +19,9 @@ This file stores definition for class Severity that is used in warn_patterns.
 """
 
 
-# pylint:disable=old-style-class
+# pylint:disable=too-few-public-methods
 class SeverityInfo:
+  """Class of Severity Info, part of a Severity object."""
 
   def __init__(self, value, color, column_header, header):
     self.value = value
@@ -29,7 +30,7 @@ class SeverityInfo:
     self.header = header
 
 
-# pylint:disable=old-style-class
+# pylint:disable=too-few-public-methods
 class Severity:
   """Class of Severity levels where each level is a SeverityInfo."""