Removed references to unused attributes.
Removed references to unused attributes.

expression.Expr.BUFFERTIMES and CHUNKTIMES were removed from the expression.Expr docstring.

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