Implementation of IMAP IDLE

- Use a newer version of imaplib
 - Hijack the keepalive process to send IDLE instead of NOOP

offlineimap/repository/IMAP.py

@@ -74,9 +74,13 @@ class IMAPRepository(BaseRepository):
         self.imapserver.close()
 
     def getholdconnectionopen(self):
+        if self.getidlefolders():
+            return 1
         return self.getconfboolean("holdconnectionopen", 0)
 
     def getkeepalive(self):
+        if self.getidlefolders():
+            return 29*60
         return self.getconfint("keepalive", 0)
 
     def getsep(self):
@@ -145,8 +149,14 @@ class IMAPRepository(BaseRepository):
     def getreference(self):
         return self.getconf('reference', '""')
 
+    def getidlefolders(self):
+        localeval = self.localeval
+        return localeval.eval(self.getconf('idlefolders', '[]'))
+
     def getmaxconnections(self):
-        return self.getconfint('maxconnections', 1)
+        num1 = len(self.getidlefolders())
+        num2 = self.getconfint('maxconnections', 1)
+        return max(num1, num2)
 
     def getexpunge(self):
         return self.getconfboolean('expunge', 1)