Add .mailmap

Coalesce together commits by the same person in git-shortlog(1).

For people with different aliases, prefer full names over abbreviations
or nick names. For people with different email addresses, use the most
recent email address.

.mailmap

@@ -0,0 +1,14 @@
+Abdel-Rahman <abodyxplay1@gmail.com>
+Brian Johnson <brian@sherbang.com>
+Carlo Teubner <carlo.teubner@gmail.com>
+Mark Edgington <edgimar@gmail.com>
+Leo Famulari <leo@famulari.name>
+Marian Beermann <public@enkore.de>
+Thomas Waldmann <tw@waldmann-edv.de>
+Dan Christensen <jdc@uwo.ca> <jdc+github@uwo.ca>
+Antoine Beaupré <anarcat@koumbit.org> <anarcat@debian.org> <anarcat@users.noreply.github.com>
+Hartmut Goebel <h.goebel@crazy-compilers.com> <htgoebel@users.noreply.github.com>
+Michael Gajda <michaelg@speciesm.net> <michael.gajda@tu-dortmund.de>
+Milkey Mouse <milkeymouse@meme.institute> <milkey-mouse@users.noreply.github.com>
+Ronny Pfannschmidt <opensource@ronnypfannschmidt.de> <ronny.pfannschmidt@redhat.com>
+Stefan Tatschner <rumpelsepp@sevenbyte.org> <stefan@sevenbyte.org>