New location-based components

These are new location-based components, which aim to solve outstanding issues such as #278.

The new components wrap the three.js location-based AR.js API and are internally simpler and thus easier to maintain and debug. Thus, they are likely to see more active development and bug-fixes so it is recommended to try them first, and if they do not work for you, try the original components instead.

Please see the example to see how to use these components.