'rot' parameter to DataFrame.boxplot not applied to some axes when multi-panel plot is produced using 'by'

[saffsd]

Minimal snippet:

import pandas as pd
from numpy.random import randn
import matplotlib.pyplot as plt

d = pd.DataFrame({'one':randn(5), 'two':randn(5), 'three':randn(5), 'label':['label'] * 5},
        columns = ['one','two','three', 'label'])
bp= d.boxplot(by='label', rot=45)
plt.savefig('xxx.png')

Output produced:

Issue:
The label on the left is rotated but the label on the right is not.

Versions:
pandas '0.12.0'
matplotlib '1.3.1'

[jreback]

@saffsd if you'd like to submit a PR to correct this would be great.

[sinhrks]

How about fixing as below?

• Display most bottom xticklabels on each columns with rotated (Because ENH/BUG: boxplot now supports layout #7035 hides the bottom-right axes)
• Hide xlabel as the same manner as xticklabels