API: add sort keyword to resample (like in groupby) to not sort data to the function

[jreback]

http://stackoverflow.com/questions/18411110/python-pandas-timeseries-resample-giving-unexpected-results/18411516?noredirect=1#comment27046758_18411516

[MarcoGorelli]

There's been no activity here in nearly a decade, and it's easy to just sort before calling resample - OK to close this?

[mroeschke]

Agreed, closing