fix for crash on startup trying to post a toast too early
MoveableActor to use the RootActor position field
first draft of solving WifiPointActor positions through forces, working for single scan points.
tweaked and cleaned stuff up, made a maths util class for the static mathematical functions t hat may be used elsewhere, added handling for mass.
WifiScanActor can now reciprocate the force of the point connections, allowing it to be moved.  Made it 100x heavier than points, to reduce the madness.
load point connections for scan actors
not sure what happened in that last commit, but NOW we're loading the connections for scan actors...
Added touch handling to the graphics view, allowing the rootnode to be translated and flung by interactions.  Also detects taps, though there is no handling for it.
Engine is calling graphics updates to animate the rootnode's translation, which feels a bit weird.  Maybe I'll come up with a better solution, but this works nicely for now!