Added option to disable interpolation

This PR adds an option to disable interpolation (when images are upscaled) to the image viewer.
See Trac: https://trac.openmicroscopy.org.uk/ome/ticket/12479

![image](https://cloud.githubusercontent.com/assets/6575139/4091136/4875c316-2f85-11e4-8110-43b94d264308.png)

Testing:
Open a small image with the full image viewer, zoom to > 100% and check that there is no interpolation/anti-aliasing done, when the checkbox is not ticked.

@gusferguson : I simply placed the checkbox in the toolbar; can be easily moved somewhere else, renamed, etc.
@jburel : If interpolation is disabled, I had to use Graphics2D (instead of this external mortennobel library), but I think this isn't a problem, is it?