fix celltoolbar layout on FF
fix button css
remove one useless element
Merge pull request #2876 from Carreau/fixctff

fix celltoolbar layout on FF

Ok, bug was due to an extra empty div... This seem to lok ok on both FF and Chrome OS X.

Think of adding 
$.getScript('/static/js/celltoolbarpresets/example.js')

to your custom.js to fully test.