Added ROI filtering option

RFE: Filter by ROI, https://trac.openmicroscopy.org.uk/ome/ticket/12014

Added an ROI option similar to the Rating option to the Filter dialog:

![image](https://f.cloud.github.com/assets/6575139/2438631/1986aab0-adf4-11e3-80fb-b1031e8e5eb9.png)