Fix move click target

The javascript to get the data attribute from the td whether or not there was a piece/img in the cell is now cleaner, just uses the .closest() jquery method to select the td always. It(.closest) starts with the calling element so it can get itself as when there is no piece/img in the cell, but when there is an image it will traverse to the td.

There are two commits below because I saw there was extraneous stuff in the first commit (after the pull request was up), the second one is just the refactored bit of javascript needed on the select page.