SUPPORTERS: another late addition.
gtk-murrine-engine: New formula

Added gtk-murrine-engine formula: a GTK2 engine that features a glassy
look. This formula is written based on gtk2-murrine MacPorts Portfile (https://trac.macports.org/browser/trunk/dports/gnome/gtk2-murrine/Portfile).
Merge branch 'gtk-murrine-engine' of https://github.com/ochaochaocha3/homebrew into gtk-murrine-engine