Easy JSHint cleanup

Did a pass of all of our javascript with JSHint, and cleaned up missing semicolons and strict equality suggestions it pointed out.

I did not deal with any other issues, of which there were many, and I didn't touch any of the jquery javascript because (obviously) we didn't write it.
`box.value` will be a string so strict equality against 0 will always return false here. We should wrap this in a `parseInt(box.value, 10)` before using strict equality against 0.