Add a .mailmap file

So I was checking out minetest and wondered how many developers there are
and how they development community is setup and such, so I decided to have
a look at the git shortlog. There were lot of double entries for some
persons, so it was harder to estimate the number of people involved.

By adding a .mailmap file, the overview of the authors is much improved
For details on the .mailmap file, see
https://www.kernel.org/pub/software/scm/git/docs/git-shortlog.html

Signed-off-by: Stefan Beller <[email protected]>

.mailmap

@@ -0,0 +1,33 @@
+0gb.us <[email protected]> <[email protected]>
+Calinou <[email protected]> <[email protected]>
+Perttu Ahola <[email protected]> celeron55 <[email protected]>
+Perttu Ahola <[email protected]> celeron55 <celeron55@armada.(none)>
+Craig Robbins <[email protected]> <[email protected]>
+Diego Martínez <[email protected]> <[email protected]>
+Ilya Zhuravlev <[email protected]> <[email protected]>
+kwolekr <[email protected]> <[email protected]>
+PilzAdam <[email protected]> PilzAdam <[email protected]>
+PilzAdam <[email protected]> Pilz Adam <[email protected]>
+PilzAdam <[email protected]> PilzAdam <[email protected]>
+proller <[email protected]> <[email protected]>
+proller <[email protected]> <[email protected]>
+RealBadAngel <[email protected]> <[email protected]>
+RealBadAngel <[email protected]> <[email protected]>
+Selat <[email protected]> <[email protected]>
+ShadowNinja <[email protected]> ShadowNinja <[email protected]>
+Shen Zheyu <[email protected]> arsdragonfly <[email protected]>
+Pavel Elagin <[email protected]> elagin <[email protected]>
+Esteban I. Ruiz Moreno <[email protected]> Esteban I. RM <[email protected]>
+manuel duarte <[email protected]> manuel joaquim <[email protected]>
+manuel duarte <[email protected]> sweetbomber <ffrogger _zero_ at yahoo dot com>
+Diego Martínez <[email protected]> kaeza <[email protected]>
+Diego Martínez <[email protected]> Diego Martinez <[email protected]>
+Lord James <[email protected]> Lord89James <[email protected]>
+BlockMen <[email protected]> Block Men <[email protected]>
+Sfan5 <[email protected]> sfan5 <[email protected]>
+DannyDark <[email protected]> dannydark <[email protected]>
+Ilya Pavlov <[email protected]> Ilya <[email protected]>
+Ilya Zhuravlev <[email protected]> xyzz <[email protected]>
+sapier <Sapier at GMX dot net> sapier <sapier AT gmx DOT net>
+sapier <Sapier at GMX dot net> sapier <sapier at gmx dot net>
+