Issue: Gallery Tag Improvements

This issue was tied to this: https://www.vaultwiki.org/issues/3813/
In our efforts to make a better looking screen shots page, we ended up upgrading the wiki's GALLERY tag with some Javascript functionality.

First, if the GALLERY tag has the rows attribute, it will turn into a scrollable widget when the number of rows of images exceeds the given amount. The tag will automatically use the perrow attribute to determine the maximum number of images per row. If the perrow attribute is omitted, the tag will assume you want all the images in one row (for responsiveness), and the scrollable widget will not be triggered.

If the GALLERY tag has the feature attribute (set to a non-zero, non-false value), it will highlight the first item in the gallery by showing the full-size version above the gallery list. If you click on another image in the list, the full-size version of the clicked image will be shown in the featured slot.

On the screen shots page we are using rows="1" feature="true" for a nice effect.

You will notice that once the GALLERY "pops" into Javascript mode, new styling takes effect. The colors for this variant of the GALLERY can be controlled by new Style Variables.

This function is still in progress. There are still some changes that should be made to improve the usability of the scrollable option.