[NEXUS-2834] Regenerate maven metadata when artefact is deleted

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Fix assumptions about trash folder (it should expect that no artifacts/metadata files are present)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
JavaDoc

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-2834] UT to verify that maven metadata is regenerated after an artifact is deleted

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-2834] Change test name to denote what has been tested

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-2834] Change warn message in case that metadata cannot be maintained

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge pull request #826 from sonatype/nexus-2834-rebuild-maven-meta-on-delete

REVIEW: [NEXUS-2834] Rebuild maven metadata when item gets deleted