Add an URL dispatcher

[ybon]

Resources:
- https://wiki.ubuntu.com/URLDispatcher
- https://code.launchpad.net/~ted/ubuntu-clock-app/url-dispatcher/+merge/201536

Not sure which protocol to expose: map://?

Not sure how conflict between URL dispatchers will be handled.

Not sure how other apps will now/decide to use such an URL protocol.

[Sam Bull (dreamsorcerer)]

You should expose the geo:// URI, which appears as:
    geo:<lat>,<lon>[,<alt>][;u=<uncertainty>]

http://en.wikipedia.org/wiki/Geo_URI

In addition, there is another (not yet official) URI, which is maps://:
    maps:q=<physical location>

https://www.iana.org/assignments/uri-schemes/prov/maps

I'm guessing the maps:// URI should just open the map with the parameter as a search term, while the geo:// URI gives an exact location, and the uncertainty parameter can be used to set the circle size similar to how the user's position is displayed.