BUG: Series.sort will raise a ValueError (rather than a TypeError) on sorting an
     object that is a view of another (GH5856`, GH5853)

API: DataFrame._ixs will properly record a cache change (similar to _get_item_cache)
Merge pull request #5859 from jreback/series_view

rework Series.sort is_view check on underlying ndarray inplace sort (GH5856)