lib-storage: Hide and rmdir \NoSelect leaf mailboxes with NO-NOSELECT If the leaf is successfully rmdir()ed, rmdir() also its parents. This doesn't work perfectly with if there are multiple levels of \NoSelect mailboxes. For example with "a/b/c" the listing will already have returned "a" and "a/b" before it reaches the "a/b/c" code, which will rmdir all of them, but it's a bit too late at that point. It's too much work to fix though, and the situation will be fixed on the next list anyway.

lib-storage: Add mailbox_list_delete_finish_ret() This simplifies deletion logic for mailbox list backends.

lib-storage: mailbox_list_delete_finish() - Return whether anything was deleted

lib-storage: Add comments to mailbox-list-delete.h

lib: Changed unlink_directory() API to return error string. There are many different reasons why it could fail, which a simple errno can't very clearly indicate.

lib-storage: Added initial implementation for layout=index. The idea is that all of the mailbox names only exist in the mailbox list index. Storage directories use mailbox GUIDs. This avoids all kinds of race conditions with mailbox renames. mailbox_list_index=yes is required for this layout to work. There are probably still some race conditions within the indexing code itself. Also error recovery is missing.

Removed all the "enum foo;" declarations. They didn't seem to be very standard. Old gcc versions warn about them and C++ code doesn't like them.

lib-storage: mailbox_delete() for a symlink now removes the symlink instead of expunging mails.

lib-storage: Fixed deleting symlinked mailbox.

lib-storage: When renaming a mailbox, make sure any unnecessary directories get deleted. --HG-- branch : HEAD

lib-storage: Mailbox deletion API changed. Mailbox deletion should now be free of race conditions. The actual file deletion code is now responsibility of mailbox_list backend. --HG-- branch : HEAD