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New Features:
- `change` option to .utils.make_metadata_updater
(a function(object, logger), called before reindexing)
Improved exception handling:
- When catching IOErrors while reindexing, we inspect the message text;
quite likely it's PIL (or Pillow) objecting to an unsupported image format.
If so, we log the error, return False, and proceed to the next object.
This usually implies the indexes and metadata refresh for the respective object to *fail,*
but for the whole rest we should succeed.
*Of course,* the error handling should better happen in the respective indexer!
- `ConflictError` and `KeyboardInterrupt` exceptions during reindexing are logged
and re-raised.
[tobiasherp]