I don't understand why getSource throws an Exception when a property can be
found in multiple configurations. If the property is not a list or if
escaping is disabled then the value from the first Configuration the key is
found in will be used. Shouldn't an Exception only be thrown when the value
is constructed by merging values from two Configurations? (This only seems
to happen if a String with the escape character is present). I'm writing a
class that extends CombinedConfiguration and I wanted to changed this
behavior so that it works that way but unfortunately findSourceConfiguration
is private instead of protected so I can't reimplement getSource without
also reimplementing findSourceConfiguration.
