* filter-driver.c (filter_driver_new): kill
filter_driver_set_session and filter_driver_set_rules and instead
make filter_driver_new take the rules and a callback function it
can use to turn URIs into folders.
(open_folder): Use the callback function rather than calling camel
directly: some URIs need special handling to turn them into stores
and folders correctly, so let the mailer do that.
svn path=/trunk/; revision=3859
f1701f224d