Move setting to the storage app

The setting COMMON_TEMPORARY_DIRECTORY is now
STORAGE_TEMPORARY_DIRECTORY.

Move file related utilities to the storage app.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/django_gpg/classes.py

@@ -6,7 +6,7 @@ import shutil
 
 import gnupg
 
-from mayan.apps.common.utils import mkdtemp
+from mayan.apps.storage.utils import mkdtemp
 
 
 class GPGBackend(object):