OMG it's not needed!!!!!!!!!? Rated 5 out of 5 stars
During one of the many updates a long while back Firefox move the new tab button to the tab bar. this was great however 1. it took up valuable space on my tab bar ( of 100+/- tabs ) and 2. it was annoying to have two tab buttons and be used to using one of them.
So unbeknownst to me something happened.
I went to set up another Firefox profile and I was going over the various add-ons that i needed to install from my main profile. ( one or 2 profiles was not enough, I have 4 instances of Firefox that I can open and 6 profiles. ) and I installed this add-on and I couldn't figure out why I wasn't getting the new tab button to go away. i disabled, I restarted, I uninstalled and reinstalled, I thought it was my horrible Internet connection with Hughes-net. ( i actually had downloads. download and say they were done and they were not, as they would not open. it was only a 20MB VLC download. )
so apparently during one of the last few updates you can now edit your toolbars and drag the button off. ( was that so hard Mozilla. )
So all that leaves me to say is, thank you to "sdwilsh" for this add-on.
I was so glad when I found it way back when. thank you.