BUG: _tidy_repr should not be called when max_rows is None

http://stackoverflow.com/q/22824104/190597
BLD: update 2.7 build (doc build) to use matplotlib 1.3.1
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
BUG: Arithmetic, timezone and offsets operations affecting to NaT