python3 compatibility: dict

this patch
 1.) removes the iteritems/itervalues, which were dropped in py3
     items/values are used instead
 2.) add an extra list() in a cases the list-based access is needed
     (included appending, indexing and so)
 3.) changes a sorting idiom in few places
     instead of
     foo = dict.keys()
     foo.sort()
     for i in foo:

     there is a recommended

     for i in sorted(dict.keys()):
 4.) in one occassion it removes a if dict.has_key() by simpler
   dict.get(key, default)

osc/util/cpio.py

@@ -62,7 +62,7 @@ class CpioHdr:
         self.namesize = namesize
         # != 0 indicates CRC format (which we do not support atm)
         self.checksum = checksum
-        for k,v in self.__dict__.iteritems():
+        for k,v in self.__dict__.items():
             self.__dict__[k] = int(v, 16)
         self.filename = filename
         # data starts at dataoff and ends at dataoff+filesize