Make dragging layers to rearrange them abortable with Esc/RMB

[Keavon]

Broken out from #1912:

Abort with Esc/RMB by dragging to rearrange layers (in Firefox, RMB actually confirms the action instead of aborting it, in Chrome it just does nothing).

[prathmesh703]

@Keavon is this issue resolved ? because in both browser it is showing same behavior. On clicking Esc/RMB the dragging layers are being rearranged to their original position

[Keavon]

This issue still applies. I updated the description a little to clarify.