Don't create ConfiguratorWidget if unnecessary (no windows case).
Update link configurations.
Make smoothers FPS independent (finally!).

This actually changes how smoothing works for non-wrapping
smoothers. Instead of using single-pole filter, it uses
moving average array.

Apart from that fix, invalidate all smoothers/lookaheads when source
properties are nil.
Make lookahead module use Xefis::Lookahead estimator.
Fixes in configs.