VID-2074 Allow expanded galleries to show more images

Galleries that have the expand="true" parameter set and have more than 100 images (enough to have the "show more" button show up) will now show 100 images at at time when clicking "show more" rather than 12 images at a time.
VID-2074 Response to code review on hardcoding.

Winners don't hardcode.
VID-2074 Code review update
Merge pull request #4986 from Wikia/VID-2074

VID-2074 Allow expanded galleries to show more images