StyleShare/wand — pull request #17 by conkiztador (2012-05-01 04:35:36+00:00)
Title: Throw ImportError on shared library load failure

If the MagickWand library isn't installed, wand triggers an AttributeError when it gets to this line:
```python
library.NewMagickWand.restype = ctypes.c_void_p
```
This exception falls through all the way to the orignal import of wand, e.g.:
```
from wand.image import Image
```

This pull request catches the AttributeError and raises an ImportError instead, so this can be cleanly handled by the module that imports wand.