From zenburn-emacs: add variables for black and white.
From zenburn-emacs: add undo-tree faces.
From zenburn-emacs: fix font-lock inherits.
From zenburn-emacs: add coq faces.
From zenburn-emacs: add some org-mode faces.
From zenburn-emacs: add proofgeneral faces.
From zenburn-emacs: add shell-mode faces.
From zenburn-emacs: add speedbar faces.
Don't backquote where not necessary.