Using a class varilable instead of temp files for keeping track of docs....
Using a class varilable instead of temp files for keeping track of docs.
:meth:`IpythonDirective.setup` method was using a temporary file, such
as :file:`/tmp/seen_docRANDOM`, for storing visited source document
filenames. For a document that is not visited (name not in the temporary
file), it restarts counting line numbers. Temporary file names are
selected randomly and they were not deleted from the disk upon
completion of a build. Since :meth:`.setup` picks a temp file
arbitrarily to visited status of a file is determined incorrectly.
Using a class variable resolves this problem.
Changed the directive setup function to use a class files for keeping
track of documents.
