[NEXUS-5614] Add flag about capability transition resulting in an error

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Add @since tags

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Change version to 2.4-SNAPSHOT as we added new fields to rest model

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge pull request #24 from sonatype/nexus-5614-show-errors

TRIVIAL: [NEXUS-5614] Add flag about capability transition resulting in an error