SmartRotate function added

Resolves #236

Usage

<pre lang="python"><code>

img = Image('rotated.jpg')
aligned = img.smartRotate()
aligned.show() 
</code></pre>

Examples

![f1](https://f.cloud.github.com/assets/3823490/389068/a0d933d4-a6f2-11e2-8a71-475d86946b75.jpg)


![f3](https://f.cloud.github.com/assets/3823490/389069/a0de7272-a6f2-11e2-9979-f85c7d2f6b37.jpg)