merge last unstable rev

diff --cc telemeta/models/media.py
index 6ead795210f66e15e90578ffb50050232438a135,09ae77d348be5ae47fa05543909e78096690ae74..3c8b2b10f6ff3f3ac279725f10b938ac7bc0f193
--- 1/telemeta/models/media.py
--- 2/telemeta/models/media.py
+++ b/telemeta/models/media.py
@@@ -212,10 -214,10 +214,10 @@@ class MediaCollection(MediaResource)
  class MediaCollectionForm(ModelForm):
      class Meta:
          model = MediaCollection
- 
+         
  
 -item_published_code_regex    = '[A-Za-z0-9._-]*'
 -item_unpublished_code_regex  = '[A-Za-z0-9._-]*'
 +item_published_code_regex    = collection_published_code_regex + '(?:_[0-9]{2}){1,2}'
 +item_unpublished_code_regex  = collection_unpublished_code_regex + '_[0-9]{2,3}(?:_[0-9]{2}){0,2}'
  item_code_regex              = '(?:%s|%s)' % (item_published_code_regex, item_unpublished_code_regex)
  
  class MediaItem(MediaResource):