Remove python<2.6 import workarounds (set & ssl)

'set' is builtin since python2.6, so remove the imports. Also 'ssl' exists
since 2.6 and has everything we need, so no need for conditional import
tests here anymore.

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

offlineimap/folder/Base.py

@@ -23,10 +23,7 @@ import os.path
 import re
 from sys import exc_info
 import traceback
-try: # python 2.6 has set() built in
-    set
-except NameError:
-    from sets import Set as set
+
 
 class BaseFolder(object):
     def __init__(self, name, repository):

offlineimap/folder/IMAP.py

@@ -24,10 +24,6 @@ from sys import exc_info
 from Base import BaseFolder
 from offlineimap import imaputil, imaplibutil, OfflineImapError
 from offlineimap.imaplib2 import MonthNames
-try: # python 2.6 has set() built in
-    set
-except NameError:
-    from sets import Set as set
 
 
 class IMAPFolder(BaseFolder):

offlineimap/folder/LocalStatus.py

@@ -18,13 +18,10 @@
 from Base import BaseFolder
 import os
 import threading
-try: # python 2.6 has set() built in
-    set
-except NameError:
-    from sets import Set as set
 
 magicline = "OFFLINEIMAP LocalStatus CACHE DATA - DO NOT MODIFY - FORMAT 1"
 
+
 class LocalStatusFolder(BaseFolder):
     def __init__(self, name, repository):
         self.sep = '.' #needs to be set before super.__init__()

offlineimap/folder/LocalStatusSQLite.py

@@ -23,10 +23,6 @@ try:
 except:
     pass #fail only if needed later on, not on import
 
-try: # python 2.6 has set() built in
-    set
-except NameError:
-    from sets import Set as set
 
 class LocalStatusSQLiteFolder(LocalStatusFolder):
     """LocalStatus backend implemented with an SQLite database