VIS: datetime plots x axis format: labels now rotated?
Is this a regression, or a delibarate decision? Compare dev docs (http://pandas-docs.github.io/pandas-docs-travis/visualization.html#basic-plotting-plot) with stable ones (http://pandas.pydata.org/pandas-docs/stable/visualization.html#basic-plotting-plot). 

The xaxis labels (the date/time indications) are now rotated instead of horizontal, which I personally think is not an improvement. 
