Add pylint configuration and instructions

pylint configuration file (.pylintrc) is added, and submission
instructions are updated to include pylint usage steps.

Deprecated pylint suppression (`disable-msg`) is updated in a few
modules to make it work properly with the latest version (0.26).

Change-Id: I4ec2ef318e23557a374ecdbf40fe12645766830c
diff --git a/manifest_xml.py b/manifest_xml.py
index a2a56e9..71dbdc7 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -336,7 +336,7 @@
       raise ManifestParseError("no <manifest> in %s" % (path,))
 
     nodes = []
-    for node in manifest.childNodes:  # pylint:disable-msg=W0631
+    for node in manifest.childNodes:  # pylint:disable=W0631
                                       # We only get here if manifest is initialised
         if node.nodeName == 'include':
             name = self._reqatt(node, 'name')