demosaic: fix assertion
contributors fixups

Ger/MRIG are all Ger Siemerink :)

(cherry picked from commit 13f20c242ee325e903bd0da779b98610c6748430)
Update README.md
(cherry picked from commit 46bc8f2f98b080af8405183df993763b6c4ba9db)
opencl: implement redmine issue #10219 (add a few items to nvidia_gpus.h)

(cherry picked from commit fc01612b976c7eda5162bcba1b6387056a527337)
darktableconfig: screen realestate is tight, don't waste it by default

Particularly on laptops, screen realestate is already tight, so let's not waste any of it by default

relevant to e72625e06da05e4abd7ce9e606498239e7a58ef8

(cherry picked from commit 41546fead32f23e62073d710f50c68125ded0506)
Merge remote-tracking branch 'upstream/darktable-1.6.x' into darktable-1.6.x