Don't detect Firebug based on "console.firebug" property

In-Portal has Firebug Console detection code, that creates it, when it's missing.

Started from Firefox 4.x this code is no longer possible to detect FireBug presence because of missing window.console.firebug mark, that was available before.
Also Google Chrome browser has window.console object that is pretty good too and has "log" method.

That's why I'm proposing to change how we detect console and get rid of Firebug specific checks.