dev-tools: Added script for updating copyright years in files

dev-tools: Added script for updating copyright years in files

Very simple tool which modifies the Copyright lines in all git checked-in
files with an updated year.  Lines only listing a single year (2016) will
be modified to list a range instead.

Only the Copyright lines owners of specific owners will be modified.  The
script will need to be slightly updated to cover more owners.  See the
UPDATE_COPYRIGHT_LINES line in the script for the currently set owners.

v2 - On-the-fly-commit-update: use vendor/ instead of cmocka and
     add @sophos.com to the list of copyright holders to update

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Steffan Karger <steffan@karger.me>
Message-Id: <1482173532-25132-1-git-send-email-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg13645.html
(cherry picked from commit da8f11f895bb78174d4412d82a6992c398da495a)