DOC: Clean up Sphinx Issues, fix tabs, in Cookbook

This is a follow on PR as a result of [seeing travis and sphinx render ~30 in line examples for the cookbook] (https://github.com/pydata/pandas/pull/8288#issuecomment-58734824).

Continues to address #6918

Initial PR: https://github.com/pydata/pandas/pull/8288

PS - apologies for wanting to rush the first PR.  My evening opened up unexpectedly.  Feel free to merge this latest, or provide more feedback for me to work on later. I'm going off grid for 2+ days starting oct 10th 11 PM EST.

The latest rendering is [here](https://cloud.githubusercontent.com/assets/6062071/4601203/f3dcdc76-50f0-11e4-8466-4db698bdc3b4.png):

Edit : Removed inline view of humongous rendering, still available for viewing at link above.
SOLVED!

I think.

I'm guessing github.io is running sphinx rendering using an older python version.  I think the issue was a case of division by an integer.  Fixed in the latest squash.