NEXUS-6862: Add npm static security

Also, apply same name scheme to ContentClass as we decided to go
with templates: use "npm" instead of "NPM", and this creates
consistency in generated role names like "view" role.
Merge pull request #10 from sonatype/nexus-2.10.x-NEXUS-6862-static-security

NEXUS-6862: Add npm static security