Update .mailmap to unify and clean up odd names and e-mail addresses

To make the best use of this, have a look at the --use-mailmap option.
In particular git-log and git-shortlog makes use of it.  Also search
for mailmap in the git-log man page, for more ways to use this
remapping (format strings to --pretty).

Otherwise, to make use of the mailmap remapping by default do:

     $ git config [--global] log.mailmap true

.mailmap

@@ -1 +1,13 @@
-James Yonan <[email protected]>      james <james@e7ae566f-a301-0410-adde-c780ea21d3b5>
+Adriaan de Jong <[email protected]>             <adriaan@adriaan-VirtualBox.(none)>
+David Sommerseth <[email protected]>            <[email protected]>
+Gert Doering <[email protected]>              <[email protected]>
+Gert Doering <[email protected]>              <[email protected]>
+Gert Doering <[email protected]>              <[email protected]>
+Gert Doering <[email protected]>              <[email protected]>
+James Yonan <[email protected]>                 <james@e7ae566f-a301-0410-adde-c780ea21d3b5>
+Jan Just Keijser <[email protected]>            <[email protected]>
+JuanJo Ciarlante <[email protected]>               <[email protected]>
+Karl O. Pinc <[email protected]>                     <[email protected]>
+Robert Fischer <[email protected]>        <[email protected]>
+Samuli Seppänen <[email protected]>            <[email protected]>
+Seth Mos <[email protected]>                      <[email protected]>