Currently Fisheye & Crucible use a Flash applet (ZeroClipboard-1.2.1.swf) to provide copy to clipboard functionality (checkout URL, snippet page, selection history).

Since most browsers support this directly from JavaScript via "execCommand" method:

https://www.w3schools.com/jsref/met_document_execcommand.asp
https://www.w3schools.com/howto/howto_js_copy_clipboard.asp

let's remove existing Flash applet and replace it with JavaScript.