Adding a controller - ClassPathController

Adding a ClassPathController which allows to query the current
classloader to see if it is able to resolve a class given its name,
e.g.:

http://localhost:8082/jni-info/isClassAvailable.json?class=java.lang.String

returns:
{
      "status": "available",
      "class": "java.lang.String"
}

http://localhost:8082/jni-info/isClassAvailable.json?class=java.lang.NonExistingClass

returns:
{
      "reason": "java.lang.NonExistingClass",
      "status": "unavailable",
      "class": "java.lang.NonExistingClass"
}