Don't setDaemon explicitly, it's done inherently

All ExitNotifyThreads and InstanceLimitThreads are setDaemon(True) in their
constructor, so there is no need to do that again in the code.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

offlineimap/accounts.py

@@ -291,7 +291,6 @@ class SyncableAccount(Account):
                     name = "Folder %s [acc: %s]" % (remotefolder, self),
                     args = (self.name, remoterepos, remotefolder, localrepos,
                             statusrepos, quick))
-                thread.setDaemon(1)
                 thread.start()
                 folderthreads.append(thread)
             # wait for all threads to finish

offlineimap/folder/Base.py

@@ -341,7 +341,6 @@ class BaseFolder(object):
                     target = self.copymessageto,
                     name = "Copy message from %s:%s" % (self.repository, self),
                     args = (uid, dstfolder, statusfolder))
-                thread.setDaemon(1)
                 thread.start()
                 threads.append(thread)
             else:

offlineimap/init.py

@@ -358,7 +358,6 @@ class OfflineImap:
                                  name='Sync Runner',
                                  kwargs = {'accounts': syncaccounts,
                                            'config': self.config})
-                t.setDaemon(True)
                 t.start()
                 threadutil.exitnotifymonitorloop(threadutil.threadexited)
             self.ui.terminate()

offlineimap/threadutil.py

@@ -28,8 +28,8 @@ from offlineimap.ui import getglobalui
 ######################################################################
 
 def semaphorereset(semaphore, originalstate):
-    """Wait until the semaphore gets back to its original state -- all acquired
-    resources released."""
+    """Block until `semaphore` gets back to its original state, ie all acquired
+    resources have been released."""
     for i in range(originalstate):
         semaphore.acquire()
     # Now release these.