#72 Add context to classmap when transforming JSON to Java

[aalmiray]

When converting JSON to Java, if a List/Map property is encountered (no type information available) Json-lib will lookup hints in a classMap (if provided). Problem is that the classmap comes with a very broad scope, example

class Foo {
/*should contain Foos*/
private List/*<Foo>*/ children
}

class Bar {
/*should contain Bars*/
private List/*<Bar>*/ children
}

JsonConfig jsonConfig = new Jsonconfig()
jsonConfig.rootClass = Foo
jsonConfig.classMap = ["children":Bar]
Foo foo = JSONObject.fromObject( jsonstr, jsonConfig )
assert foo.children[0] instanceof Foo // BREAKS!!