New measurement-client variant for taking readings manually.
New measurement-client variant for taking readings manually.

It uses the exact same code as the main 'probe' client but it doesn't
talk to the server at all; instead the list of landmarks to probe is
read from a local file.

zackw/active-geolocator,zackw/active-geolocator,zackw/active-geolocator,zackw/active-geolocator