Squashed 'src/libs/message-queue/' content from commit 8a473a6

git-subtree-dir: src/libs/message-queue
git-subtree-split: 8a473a6c208659cb3288d73e9903f3656761171e
Merge commit '332d5265cf18620454f53227f15bd6d966651aae' as 'src/libs/message-queue'
Complete overhaul of tests, lots of improvements, update to 2.7.0