BUG: _tidy_repr should not be called when max_rows is None

http://stackoverflow.com/q/22824104/190597
Merge pull request #6863 from unutbu/max-rows

BUG: _tidy_repr should not be called when max_rows is None
BLD: change 2.7 build to use scipy 0.13.3
DEPR: Indexers will warn FutureWarning when used with a scalar indexer and
       a non-floating point Index (GH4892)
CI: add -s to nose