Naming: fixed NPE reported by gavin on IRC
model loader #1392: do the overload trick for classes with no constructors (most likely a private one)
model loader #1392: allow protected constructors from the JDK
model loader #1392: set the visible scope everywhere we can
Test for #1392: Someone reported being allowed to invoke the protected constructor of `java.util.logging.LogManager`
Revert "model loader #1392: set the visible scope everywhere we can"

This reverts commit bd68589d7f62d51fc975052a8d60cb29ad940a21.
Ignore test for #1392: until we figure out what is needed to produce the proper error for private constructors