Long due 1.6 release containing relevant pull requests since ~2018. U…

…pdated the build system a bit as well

Release current state as 1.5.3

Release current state as 1.5.2

release current state as 1.5.1

release current state as 1.5.0

release 1.4.6

release next

release 1.4.3

release as 1.4.2

Make JsonRpcClientException public