It's really simply, just installing the “Oxigen KDE” complement. Yes, it was developed for KDE enviroment, but works fine on Cinnamon and Mate, so the steps are....
1) On FireFox Menú go to “Complements”
2) A new from open, click on “Get Complement”
3) On top screen, right side you can see the “find box”, write KDE and push <ENTER>
4) Find the complement called “Oxygen KDE 3,9,1” and push “Install”
5) On left menu, select “Apareance”, if everything is OK, you can see the complement option, and a Activate Button, Click <Activate>. And ReStart de FireFox Session.
6) Now you can deactivate the Bar Menu to get the Orange Firefox Tab, and Icons on your menu options on Firefox.
I'm using LMDE 201204