[NXCM-5131] Set itemMaxAge in a repository resource even if the repository does not have maven-specific artifact/metadataMaxAge
[NXCM-5131] Fix repo REST resource to set itemMaxAge on non-maven repositories for config changes
Add support for getting some repository properties
[NXCM-5131] Add IT for repo creation default values
Update project versions and docs
Add license headers
Build cleanup