hope support the "|" separator

[tospery]

like,
mutating func mapping(map: Map) {
id <- map["areaId|serverId"]
}
when has not areaId, use serverId.
can modify the follow code to support.
private func subscript(key: String, nested: Bool? = nil, delimiter: String = ".", ignoreNil: Bool = false) -> Map {
// save key and value associated to it
currentKey = key
keyIsNested = nested ?? key.contains(delimiter)
nestedKeyDelimiter = delimiter

	if mappingType == .fromJSON {
		// check if a value exists for the current key
		// do this pre-check for performance reasons
		if keyIsNested {
			// break down the components of the key that are separated by delimiter
			(isKeyPresent, currentValue) = valueFor(ArraySlice(key.components(separatedBy: delimiter)), dictionary: JSON)
		} else {
			var object = JSON[key]

// add this code
if object == nil && key.contains(delimiter) {
let components = key.components(separatedBy: delimiter)
for item in components {
object = JSON[item]
if object != nil {
break
}
}
}
// end add

            var isNSNull = object is NSNull
			isKeyPresent = isNSNull ? true : object != nil
			currentValue = isNSNull ? nil : object
		}
		
		// update isKeyPresent if ignoreNil is true
		if ignoreNil && currentValue == nil {
			isKeyPresent = false
		}
	}
	
	return self
}