Add @Nullable and @Nonnull annotations
Refactor security APIs a little
MethodHandle's ParameterResolver now receives a MapEx instead of a Map
Added RealmManager service implementation
Add ConcurrentHashMapEx class
Add UserManager implementation
Add FileVisitorAdapter class, serving as a base class for FileVisitor<Path> implementations
Annotate 'Password.getPassword()' method as @Nullable
Add local users realm implementation