BUG: Repeated timeseries plot may result in incorrect kind
Must be revisited after #7717.

Repeated line and area plot may result incorrect if it requires resampling.

```
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

fig, axes = plt.subplots(2, 2, figsize=(7, 5))
np.random.seed(1)

df1 = pd.DataFrame(np.random.rand(5, 2), pd.date_range('2011-01-01', periods=5, freq='D'))
df2 = pd.DataFrame(np.random.rand(2, 2), pd.date_range('2011-01-01', periods=2, freq='M'))

df1.plot(kind='line', ax=axes[0][0], legend=False)
df2.plot(kind='area', ax=axes[0][0], legend=False)

df1.plot(kind='area', ax=axes[1][0], legend=False)
df2.plot(kind='line', ax=axes[1][0], legend=False)

df2.plot(kind='line', ax=axes[0][1], legend=False)
df1.plot(kind='area', ax=axes[0][1], legend=False)
# ValueError: Argument dimensions are incompatible

df2.plot(kind='area', ax=axes[1][1], legend=False)
df1.plot(kind='line', ax=axes[1][1], legend=False)
```
### Result using current master
- line with low  freq -> area with high freq results in `ValueError` (top-right axes)
- area with low  freq -> line with high freq results in all lines, not area (bottom-right axes)
  ![figure_ng](https://cloud.githubusercontent.com/assets/1696302/3560065/dd93e976-0958-11e4-83e1-acd1dbffa1df.png)
### Result after fix

![figure_ok](https://cloud.githubusercontent.com/assets/1696302/3560079/622f2eb6-0959-11e4-90ed-5e7eee5dea52.png)

Rebased. I think this can be reviewed.
 thanks!
