Merge pull request #26 from danielballan/master

cosmetic updates
Merge pull request #27 from danielballan/master

CLN: Stop trying to call matplotlib.use
ENH: Add maxsize to locate.
Merge pull request #28 from danielballan/master

ENH: Add maxsize to locate.
Merge pull request #29 from danielballan/master

changes for compatibility with new pandas release 0.13