core/packs/: Add a golden-ratio pack

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
packages/emacs-powerline: New package

Use it on bombadil and hadhodrond for an enhanced mode line.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
core/packs/pack-highlights: Fix the nrepl flash

We need to clear the foreground & background of the flash too.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>