Added ability to disable fsync()

Passed config to LocalStatus and Maildir folders so they can look
up the fsync status

offlineimap.conf

@@ -98,6 +98,16 @@ ignore-readonly = no
 #
 # socktimeout = 60
 
+# By default, OfflineIMAP will use fsync() to force data out to disk at
+# opportune times to ensure consistency.  This can, however, reduce
+# performance.  Users where /home is on SSD (Flash) may also wish to reduce
+# write cycles.  Therefore, you can disable OfflineIMAP's use of fsync().
+# Doing so will come at the expense of greater risk of message duplication
+# in the event of a system crash or power loss.  Default is fsync = true.
+# Set fsync = false ot disable fsync.
+#
+# fsync = true
+
 ##################################################
 # Mailbox name recorder
 ##################################################