Merge EnhancedConfiguration with Configuration
Extract SecurityModelConfiguration iface
Fix license/javadoc
Merge remote-tracking branch 'origin/NEXUS-7336-osecurity-step-3' into NEXUS-7336-osecurity-step-4

Conflicts:
	plugins/basic/nexus-site-repository-plugin/src/main/java/org/sonatype/nexus/repository/site/plugin/config/SiteRepositorySecurityConfigurationModifier.java
Implement orient SecurityModelConfiguration
Do not longer save the config
Do not longer save the config
Use update instead of add/remove
Merge remote-tracking branch 'origin/NEXUS-7336-osecurity-step-3' into NEXUS-7336-osecurity-step-4
Remove unused method
Create user role mappings in same transaction as the user
Validate that static/dynamic resources do not have users/mappings
Use update instead of remove/add
Create user role mappings in same transaction as the user
Drop dead code
Delete mappings when user is removed
Use update instead of remove/add
Get rid of concurrent configuration manager
Directly lookup ResourceMergingConfigurationManager