Moving lineno into generic visitor
Moving lineno into generic visitor

Currently each specific node visitor type that we implement adds
line number to the context.  Rather than do it separately in each
place we can just do it once in the generic node visitor.

Change-Id: I32cd96d2290a08ab603fa875466da8a8d6926950

pombredanne/bandit,austin987/bandit,stackforge/bandit,pombredanne/bandit,chair6/bandit,stackforge/bandit