'Remove an association if it exists. Do nothing if it does not.
(str, str) -> bool'

def removeAssociation(self, server_url, handle):

    assoc = self.getAssociation(server_url, handle)
    if (assoc is None):
        return 0
    else:
        filename = self.getAssociationFilename(server_url, handle)
        return _removeIfPresent(filename)
