Fix toolbar color/height on Linux

Fixes #104.
Issue #45 (Add hover style for ancestor path buttons)
https://github.com/firebug/firebug.next/issues/45
Part 1: Split ancestor path separator from ancestor path button
Issue #45 (Add hover style for ancestor path buttons)
https://github.com/firebug/firebug.next/issues/45
Part 2: Added the hover style and adjusted the margins between buttons
Merge branch 'issue45'
A comment + note
Merge branch 'master' of github.com:firebug/firebug.next
Merge branch 'master' of github.com:firebug/firebug.next into issue108
#108 call super object