Change config system to use new Gson powered json config system

Changed over to a JSON based config system powered by gson, due to the
simplicity with working with the library and being able to directly
serialize/deserialize any number of objects into discrete config files. The
values within the files have to be set to be exposed within the JSON by the
@Expose annotation provided by gson. This means that the files can also be used
for any static data that won't be changing as well.