Thumbnail figure

Adding support for "Thumbnail Figure" in web.

Script dialog has same functionality as Insight, but shows a preview of the Figure while updating parameters, in particular, sorting images by Tag.
The tag sorting strategy has changed a little in the script and UI: If an image is tagged by more than one of the chosen tags, it is shown "nested" in a hierarchy defined by the order the tags were chosen.

To test, need to have a couple of datasets with images tagged with various tags:
 - Choose a number of images OR one or more datasets
 - Launch Publication Options > Thumbnail Figure (toolbar top of right panel)
 - Adjust "Images per row", choose Tags with/without "Include all thumbnails".
 - Add and remove Tags and see if the thumbnails layout "makes sense". The thumbnails are grouped first by the first tag(s) chosen, and then grouped by subsequent tags IF they are tagged by more than 1 Tag.
 - Compare the figure "Preview" in web UI and the figure generated by the script - should be equivalent, except that the script doesn't yet support "hierarchical" nesting of multiply tagged images (simply listed in order). See https://github.com/ome/scripts/pull/27 for corresponding Script PR.

NB: This layout is a New feature, so it might need some usability feedback.

![Screen shot 2013-04-09 at 00 11 21](https://f.cloud.github.com/assets/900055/354514/af5e20c4-a0a1-11e2-9664-84182b508463.png)