Drop LibBalsaMailbox:is_directory
It was a write-only flag.
- libbalsa/mailbox.c (libbalsa_mailbox_init), (libbalsa_mailbox_set_msg_tree_changed):
- libbalsa/mailbox.h:
- libbalsa/mailbox_maildir.c (libbalsa_mailbox_maildir_new):
- libbalsa/mailbox_mbox.c (libbalsa_mailbox_mbox_new):
- libbalsa/mailbox_mh.c (libbalsa_mailbox_mh_new):
The start of a more disciplined era! I don't know how long LibBalsaMailbox:is_directory has been dead wood, but it is now, and I can't think of any future need for it, so I propose that we drop it. This commit could always be reverted if a need arises.
Thoughts?