Catimg plugin

`catimg` allows to print pictures to the stdout using `convert` (ImageMagick)

![drunk](https://f.cloud.github.com/assets/664177/1708948/b5d14bb2-6116-11e3-8acb-8cee74fc0ec9.png)

````
Usage catimg [-h] [-w width] [-c char] img
By default char is "  " and w is the terminal width
```