Hunterised version of v19.23

Official v19.23 version with standard hunterisation changes

Hunterised version of v19.22

Official v19.22 plus hunterisation extras

Huntersised v19.21

Official v19.21 with hunterisation patches cherry-picked from previous versions.

Hunterised version of 19.19 with OpenCV updates

Hunterised version of upstream 19.19 with the addition of recent OpenCV changes for davisking#1949 and davisking#1963 merged from upstream master.

Hunterised version of 19.19

Cherry pick the ruslo changes made to 19.17 on top of upstream 19.19