Ran 2to3 on pillar + some manual fixups

The 'manual fixups' are:

- incorrect use of dict.items() where dict.iteritems() was meant; this
  results in list(dict.items()), which I changed to dict.items().
- removal of 'from __future__ import' lines, which 2to3 changes into
  empty lines; I removed the empty lines.

pillar/config.py

@@ -81,7 +81,7 @@ FILE_LINK_VALIDITY = defaultdict(
 )
 
 # Roles with full GET-access to all variations of files.
-FULL_FILE_ACCESS_ROLES = {u'admin', u'subscriber', u'demo'}
+FULL_FILE_ACCESS_ROLES = {'admin', 'subscriber', 'demo'}
 
 # Client and Subclient IDs for Blender ID
 BLENDER_ID_CLIENT_ID = 'SPECIAL-SNOWFLAKE-57'
@@ -119,7 +119,7 @@ SHORT_CODE_LENGTH = 6  # characters
 # People are allowed this many bytes per uploaded file.
 FILESIZE_LIMIT_BYTES_NONSUBS = 32 * 2 ** 20
 # Unless they have one of those roles.
-ROLES_FOR_UNLIMITED_UPLOADS = {u'subscriber', u'demo', u'admin'}
+ROLES_FOR_UNLIMITED_UPLOADS = {'subscriber', 'demo', 'admin'}
 
 
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