Address "unsafe CPOW usage" warnings

[arantius]

I'm seeing them now for:

Line 266 and 270 of browser.js, in:

function GM_showPopup(aEvent) {
  function urlsOfAllFrames(contentWindow) {
    var urls = [contentWindow.location.href];
    function collect(contentWindow) {
      urls = urls.concat(urlsOfAllFrames(contentWindow));
    }
    Array.prototype.slice.call(contentWindow.frames).forEach(collect);
    return urls;
  }

The var urls = ... and the Array.prototype.slice... lines. Line 17, 23, and 28 of windowId.js.

Maybe others I haven't noticed yet.

[janekptacijarabaci]

Current:

[janekptacijarabaci]

I've pushed a fix to the testing branch: master...janekptacijarabaci:_testBranch_unsafe_CPOW_usage

The suggestion (for example).
It is necessary to test all options!

The warning: Thus it will not work in Firefox 24- (e.g. PaleMoon)! This works in Firefox 25+

The new solution to the issue: #2282

[arantius]

Merged by hand.

[arantius]

This should be in 3.5beta1; let me know what you think:
https://addons.mozilla.org/firefox/downloads/file/354560/greasemonkey-3.5beta1-fx.xpi?src=devhub