when jruby is not coming from the thread.currentThread.contextClassLoader then ScriptingContainer
does not work out of the box, dito with JRubyEngineFactory using a wrong value or 'none' value for the classloader
system property (org.jruby.embed.classloader)
Merge pull request #2111 from jruby/add-testcases-to-detect-root-classloader

when jruby is not coming from the thread.currentThread.contextClassLoade...