Unifies author/committer names for log and shortlog, see shortlog for
example, before:
% git shortlog -es
45 Alexander Dahl <alex@netz39.de>
62 David Kilias <david.kilias@gmail.com>
12 David Kilias <dkdent@netz39.de>
4 Maximilian Deubel <maximilian.deubel@gmail.com>
255 Stefan Haun <tux@netz39.de>
12 dkdent <dkdent@netz39.de>
72 tux <tux@netz39.de>
After:
% git shortlog -es
45 Alexander Dahl <alex@netz39.de>
86 David Kilias <dkdent@netz39.de>
4 Maximilian Deubel <maximilian.deubel@gmail.com>
327 Stefan Haun <tux@netz39.de>
So everyone shows up only once. Also makes `git log` better readable.
Link: https://git-scm.com/docs/gitmailmap
