BUG: bar plot can now handle bottom and left kw properly

[sinhrks]

Actually not a bug, but allows bar and barh plot to accept bottom and left kw respectively to specify the starting point.

Currently, passing bottom or left keyword results in TypeError

import pandas as pd
import numpy as np
df = pd.DataFrame(np.random.randn(5, 5))
df.plot(kind='bar', bottom=1, ax=axes[0])
# TypeError: bar() got multiple values for keyword argument 'bottom'

After fix

import matplotlib.pyplot as plt
fig, axes = plt.subplots(1, 2)

df = pd.DataFrame(np.random.randn(5, 5))
df.plot(kind='bar', bottom=1, ax=axes[0])

df2 = pd.DataFrame(np.random.rand(5, 5))
df2.plot(kind='barh', left=[1, 2, 3, 4, 5], stacked=True, ax=axes[1])

[jreback]

maybe put in enhancements

[jreback]

@TomAugspurger pls review when you can

[TomAugspurger]

I'm fine labeling this as a bug. **kwargs is supposed to pass along all the args of the original matplotlib function/method. left and bottom are args for bar.

[TomAugspurger]

Merged via 4adc6fa

Thanks @sinhrks