Bug 20720: Found some more sponsors to add to 'about'

Bug 20720: Found some more sponsors to add to 'about'

git log|grep -i "sponsored-by"|sort -n | uniq
git log|grep -i "sponsored by"|sort -n | uniq

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 5367bfcabd395c926be1c8e215d0e8c2eb76898f)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit bb1d2d9ee0644692f010b29a886a46c785aa9159)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>