Get rid of masquerading as anonymous (sort of)

First off, masquerading as anonymous is beneficial to some users, so I suggest moving that functionality to a sub module that ships with masquerade.

Reasoning:

Pressflow is a Drupal distro for high-performance sites. One of its features is that it allows for Anonymous user sessions to not be stored unless they have something in the $_SESSION variable... like a message is being set. On a busy site, this is a great performance boost as the session table is kept small.

Masquerade puts and keeps an entry in the $_SESSION variable, negating the performance boost.

If this feature could be (1) moved into a separate sub module or (2) be switched off, it would be very beneficial to large sites which still need Masquerade functionality.