This changeset also brings a couple of changes:
* rrheaders and rcheaders are dropped from html_writer.Table's constructor.
They weren't used at all and it was dead code. This simplified some
if statements.
* _is_attribute_property is used to look for a property assignment
instead on relying on a different implementation.
With this change, we moved away from depending on logilab-common,
having in Pylint all the components that were used from logilab-common.
The API should be considered an implementation detail and can change at
some point in the future.
Closes issue #621.
