A+C: add Mats Lidell. He signed the agreement with the Sweden email

address, but his changelist is under the Gmail address.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6248069

AUTHORS

@@ -138,6 +138,7 @@ Markus Duft <markus.duft@salomon.at>
 Martin Neubauer <m.ne@gmx.net>
 Mateusz Czapliński <czapkofan@gmail.com>
 Mathieu Lonjaret <mathieu.lonjaret@gmail.com>
+Mats Lidell <mats.lidell@cag.se>
 Matthew Horsnell <matthew.horsnell@gmail.com>
 Micah Stetson <micah.stetson@gmail.com>
 Michael Chaten <mchaten@gmail.com>

CONTRIBUTORS

@@ -205,6 +205,7 @@ Markus Duft <markus.duft@salomon.at>
 Martin Neubauer <m.ne@gmx.net>
 Mateusz Czapliński <czapkofan@gmail.com>
 Mathieu Lonjaret <mathieu.lonjaret@gmail.com>
+Mats Lidell <mats.lidell@cag.se> <mats.lidell@gmail.com>
 Matt Jones <mrjones@google.com>
 Matthew Horsnell <matthew.horsnell@gmail.com>
 Maxim Pimenov <mpimenov@google.com>