[Checkins] [zopefoundation/Products.ZCatalog] 8c7fb9: Use `@implementer` class decorator.

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/Products.ZCatalog
  Commit: 8c7fb9dce44ac23872c8dd920a946af93c440833
      https://github.com/zopefoundation/Products.ZCatalog/commit/8c7fb9dce44ac23872c8dd920a946af93c440833
  Author: Hanno Schlichting <hanno at hannosch.eu>
  Date:   2016-09-13 (Tue, 13 Sep 2016)

  Changed paths:
    M CHANGES.rst
    M src/Products/PluginIndexes/CompositeIndex/CompositeIndex.py
    M src/Products/PluginIndexes/DateIndex/DateIndex.py
    M src/Products/PluginIndexes/DateRangeIndex/DateRangeIndex.py
    M src/Products/PluginIndexes/DateRangeIndex/tests.py
    M src/Products/PluginIndexes/PathIndex/PathIndex.py
    M src/Products/PluginIndexes/TopicIndex/FilteredSet.py
    M src/Products/PluginIndexes/TopicIndex/TopicIndex.py
    M src/Products/PluginIndexes/unindex.py
    M src/Products/ZCTextIndex/BaseIndex.py
    M src/Products/ZCTextIndex/CosineIndex.py
    M src/Products/ZCTextIndex/HTMLSplitter.py
    M src/Products/ZCTextIndex/Lexicon.py
    M src/Products/ZCTextIndex/NBest.py
    M src/Products/ZCTextIndex/OkapiIndex.py
    M src/Products/ZCTextIndex/ParseTree.py
    M src/Products/ZCTextIndex/PipelineFactory.py
    M src/Products/ZCTextIndex/QueryParser.py
    M src/Products/ZCTextIndex/ZCTextIndex.py
    M src/Products/ZCTextIndex/tests/testPipelineFactory.py
    M src/Products/ZCatalog/CatalogBrains.py
    M src/Products/ZCatalog/ProgressHandler.py
    M src/Products/ZCatalog/ZCatalog.py

  Log Message:
  -----------
  Use `@implementer` class decorator.

Also fix test_retrieval in DateRangeIndex/tests.