BUG: Fix pandas.io.data.Options for change in format of Yahoo Option page

ENH: Automatically choose next expiry if expiry date isn't valid

COMPAT: Remove dictionary comprehension to pass 2.6 test

BUG: Add check that tables were downloaded.

ENH: Replace third_saturday function with Pandas offset

BUG: Check to make sure enough option tables are downloaded.

TST: Add sample options page during market open.

DOC: Add bug fix report to v0.15.1.txt for data.Options

BUG: Ensure that the value used for chopping is within the range of strikes.

TST: Add test for requesting out of range chop

BUG: Fix missing underlying price and quote time in first process data

BUG: Fix AM/PM on quote time

ENH: Refactor to expose available expiry dates

DOC: Update documentation for Options given Yahoo change.

DOC: Update documentation for Options given Yahoo change.

BUG: Undo accidental deletion of privat emethods