Support maildir for windows

That makes OfflineIMAP to use exclamation mark (!) instead of colon for storing
messages. Such files can be written to windows partitions. But you will probably
loose compatibility with other programs trying to read the same Maildir.

Signed-off-by: Vladimir Marek <vladimir.marek@oracle.com>
Reviewed-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

docs/MANUAL.rst

@@ -300,5 +300,26 @@ KNOWN BUGS
   * IDLE may only work "once" per refresh.  If you encounter this bug,
     please send a report to the list!
 
+* Maildir support in Windows drive
+    Maildir uses colon caracter (:) in message file names. Colon is however
+    forbidden character in windows drives. There are several workarounds for
+    that situation:
+
+   * Use "maildir-windows-compatible = yes" account OfflineIMAP configuration.
+      - That makes OfflineIMAP to use exclamation mark (!) instead of colon for
+        storing messages. Such files can be written to windows partitions. But
+        you will probably loose compatibility with other programs trying to
+        read the same Maildir.
+      - Exclamation mark was choosed because of the note in
+        http://docs.python.org/library/mailbox.html
+      - If you have some messages already stored without this option, you will
+        have to re-sync them again
+
+   * Enable file name character translation in windows registry (not tested)
+      - http://support.microsoft.com/kb/289627
+
+   * Use cygwin managed mount (not tested)
+      - not available anymore since cygwin 1.7
+
 SEE ALSO
 ========