[NEXUS-5741] Extract non maven specific file content validation to super class to be able to reuse it

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5741] Implement a p2 specific file content FileTypeValidator (including Pack2000 validator)

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5741] Configure P2 repositories to use FileTypeItemContentValidator

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Replace plexus with jsr330 and use static IDs for validator hints

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
[NEXUS-5741] Add IT for checking that P2 repository items content is validated

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge remote-tracking branch 'origin/master' into nexus-5741-p2-content-validation
[NEXUS-5741] Verify that log file contains info that content of file is invalid

Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>
Merge pull request #36 from sonatype/nexus-5741-p2-content-validation

REVIEW: [NEXUS-5741] Enable file content validation for P2 repositories
Merge remote-tracking branch 'origin/master' into nexus-2829-p2-composite-repository