Re-enable indexing in some tests so as to avoid a PerformanceWarning related with dirty columns.
Re-enable indexing in some tests so as to avoid a PerformanceWarning related with dirty columns.

git-svn-id: 0085d6b201dccfdfb2c6e7dc6ceb151af9c0ea7d@4474 1b98710c-d8ec-0310-ae81-f5f2bcd8cb94

jennolsen84/PyTables,mohamed-ali/PyTables,gdementen/PyTables,jack-pappas/PyTables,dotsdl/PyTables,cpcloud/PyTables,avalentino/PyTables,joonro/PyTables,rabernat/PyTables,rdhyee/PyTables,PyTables/PyTables,andreabedini/PyTables,dotsdl/PyTables,gdementen/PyTables,jack-pappas/PyTables,andreabedini/PyTables,rabernat/PyTables,mohamed-ali/PyTables,joonro/PyTables,tp199911/PyTables,FrancescAlted/PyTables,jennolsen84/PyTables,jack-pappas/PyTables,tp199911/PyTables,rabernat/PyTables,cpcloud/PyTables,cpcloud/PyTables,andreabedini/PyTables,gdementen/PyTables,rdhyee/PyTables,rdhyee/PyTables,mohamed-ali/PyTables,dotsdl/PyTables,jennolsen84/PyTables,FrancescAlted/PyTables,andreabedini/PyTables,jennolsen84/PyTables,tp199911/PyTables,dotsdl/PyTables,avalentino/PyTables,rabernat/PyTables,joonro/PyTables,PyTables/PyTables,joonro/PyTables,jack-pappas/PyTables,jack-pappas/PyTables,cpcloud/PyTables,rdhyee/PyTables,mohamed-ali/PyTables,gdementen/PyTables,tp199911/PyTables,FrancescAlted/PyTables,PyTables/PyTables,avalentino/PyTables