.mailmap: Entries for Alex Bennée, Deskin Miller, Vitaly "_Vi" Shukela

.mailmap: Entries for Alex Bennée, Deskin Miller, Vitaly "_Vi" Shukela

With the current .mailmap, git shortlog shows the following for these:

    11	Deskin Miller
     3	Vitaly \"_Vi\" Shukela
     1	Alex Bennee
     1	Alex Bennée
     1	Deskin Miler
     1	Vitaly _Vi Shukela

Add (e-mail based qualified) entries to .mailmap to get:

    12	Deskin Miller
     4	Vitaly "_Vi" Shukela
     2	Alex Bennée

The Shukela spelling is based on the version used consistently in the s-o-b
lines of all his patches.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>