Please describe the problem:
Using different email clients (e.g. thunderbird) to create new imap folders,
evolution does not update the folder structure. This happens when the option, in
preferences->account editor->Receiving options -> the option "Show only
subscribed folders" is not selected. 

Togeling this option and closing the account editor forces an update. It appears
that upon starting evolution, and with the "Show only subscribed folders" turned
off, that the imap folder structure is not updated.

Steps to reproduce:
1. start evolution, observe the imap folder structure. Next disable "Show only
subscribed folders" in account setting of imap entry. Close evolution
2. Use a different imap client (thunderbird), create a new imap folder, close
imap client.
3. Start evolution and obeserve folder structure, the new created folder is not
available. Only after togeling Show only subscribed folders" this happens


Actual results:
New folder is not displayed

Expected results:
Evolution should display the full imap folder structure if requested. This will
create big user confusion because most users use multiple imap clients (web
mail, thunderbird, evolution) for the same imap account

Does this happen every time?
Yes

Other information:
No