fixes entry insert when index is reverted at the same time
add a test that proves boolean index remains ok when a reindexation has
inverted the index value
BooleanIndex was wrong when index inversion occured
  when an existing content was reindexed with an opposite value.
  Fixes LP #1236354.
Merge branch 'master' of github.com:tdesvenain/Products.ZCatalog into tdesvenain-master
Put changelog entry into imperative mode.