fix #29

I confirmed that 
```
try:
    import Image
except ImportError:
    from PIL import Image
```
still conflict with pylab and possibly other packages using `from PIL import Image`

The reason might be that in PIL, when `import Image` fails, they will just do something like sys.exit() instead of throwing exceptions.

Now I simply changed it to ```from PIL import Image``` and I can use pylab in ipython with pycollada.