plt.text clips the figure when using bbox_inches='tight'

``` python
from matplotlib import pyplot as plt
plt.plot([1,2,3,4],[1,2,3,4])
plt.text(3,3,'hey\nhoo\nblah\n')
plt.savefig('test.png',bbox_inches='tight')
exit()
```

gives a tiny figure with text in the middle (no axis just part of the plot line)
