Add support for GNU Emacs

Packages describing “emacs” as local USE flag

Package “emacs” Flag Description
net-mail/notmuch Install Emacs UI (the main one)
media-sound/supercollider Enable the SCEL user interface
net-mail/mu Install the mu4e mail client
app-editors/leafpad Enable Emacs key theme

All packages providing a “emacs” USE flag (87)