About folder names

[Qiang Guo]

Hi, all

When oli pulls folders list from remote server, some folders' name
contain whitespace. This works fine on oli's side, but this naming may
cause some mail-reading-clients to omit such folders. I'm right now
using Gnus, AFAIK, which can't recognize folder names with
whitespaces. So my question is could we eliminate the whitespace in
folder names, if there is any. Instead, we could replace the whitespces
with a dot like (Sent.Mail). 

In the source code, the folder name is genereated at IMAP.py, line 286:

foldername = imaputil.dequote(name)
+foldername.replace(" ", ".")

Sorry I've never make patch or something before. I'd very like to
contribute to this project though :)

Qiang