Create a type safe replacement for Properties

Properties only allows String as key and as Value when properly used. However, one can use any Object for the key or the value. This is inappropriate from a type checking perspective. It should use String instead.

Add
PropertyMap extends LinkedHashMap<String,String>
as a replacement for
Properties extends Hashtable<Object,Object>
This will need to implement the characteristics of Properties:

• Default chaining
• getProperty(key, default)
• save and load