Updated docs with details of ex-dates for Yahoo historical actions.

Author: brotchie

docs/source/remote_data.rst

@@ -47,7 +47,7 @@ Historical stock prices from Yahoo! Finance.
     f = web.DataReader("F", 'yahoo', start, end)
     f.ix['2010-01-04']
 
-Historical corporate actions (Dividends and Stock Splits) from Yahoo! Finance.
+Historical corporate actions (Dividends and Stock Splits) with ex-dates from Yahoo! Finance.
 
 .. ipython:: python