Tools for panel creation and MCP.
Upgrade libkdtree++ to version from Tue Nov 23 19:44:51 2010 +0800.

Upgrade to commit 7bb7e830d6899214e9e896f920483ddb39c43f7b.
Create missing storage for various static constexprs.
Simplify usage of parse_(properties|settings).
Split Smoother → SmootherBase and Smoother<T> and implement Hann window.
Let PropertyObserver deal properly with smoothed output properties.

Fire callback several times after observed property changes, to ensure
that output smoothers will be processed.

Also make PropertyNodes bump its serial value only when their value
or nil-state really changes.
Configure PropertyObservers to watch output data smoothers.

Also fix some issues with time delta passed to smoothers.
Now PropertyObservers can itegrate time deltas on their own.
Add setting 'minimum-altitute-difference' to AltAcq module.
Don't draw alt-acquired arc too big nor too small on HSI.
Reorganize code in FlightDirector a bit.
Style.
Reset delta-time to 0, not to current time value.
HSI: Show 360 instead of 000.
Refactor AFCS module from private/state.

Add stub for systems/autothrottle.
Update docs.
Update config.