[maven-release-plugin] copy for tag 0.5.2

[maven-release-plugin] copy for tag 0.5.1

[maven-release-plugin] copy for tag 0.5.0

version 0.4.0

version 0.3.0

version 0.2.0

doc updates and a changelog

thread collector refactor and fix

commit for 0.1.0 version

add prometheus license