This is done to avoid a big chunk of conditionally-compiled code
in the middle of the event function.
Also separates the zoom logic from the WX_VIEW_CONTROLS object
and isolates it in a separate class behind a clearer interface.
Add some simple tests for sane steps on GTK+3-sized scroll
steps.
Replace all instances of wxLogDebug with wxLogTrace in the common and
kicad folders to prevent unwanted debugging output.
Add new trace flags for locale and screen object tracing.
The usual smattering of code policy fixes.