[PATCHv3] Improve documentation on "reference" option

[Sebastian Spaeth]

It was not clear how the reference value is used. Improve this by exposing
the internal path build system for the 'reference' option so that users
know what value is expected.
Also, explain how it impacts both nametrans and folderfilter options.

Signed-off-by: Sebastian Spaeth <Sebastian at SSpaeth.de>
---
Now with even better commit text. :-) Thanks for the suggestions.

 offlineimap.conf |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/offlineimap.conf b/offlineimap.conf
index d3be8be..72a3fa8 100644
--- a/offlineimap.conf
+++ b/offlineimap.conf
@@ -327,10 +327,14 @@ remoteuser = username
 
 ########## Advanced settings
 
-# Some IMAP servers need a "reference" which often refers to the
-# "folder root".  This is most commonly needed with UW IMAP, where
-# you might need to specify the directory in which your mail is
-# stored.  Most users will not need this.
+# Some IMAP servers need a "reference" which often refers to the "folder
+# root".  This is most commonly needed with UW IMAP, where you might
+# need to specify the directory in which your mail is stored. The
+# 'reference' value will be prefixed to all folder paths refering to
+# that repository. E.g. accessing folder 'INBOX' with reference = Mail
+# will try to access Mail/INBOX. Note that the nametrans and
+# folderfilter functions will still apply the full path including the
+# reference prefix.  Most users will not need this.
 #
 # reference = Mail
 
-- 
1.7.1