The class now has two separate methods for setting a duration or a point
value. They MUST be used appropriately, because their behavior is different.
When ::set_duration() is used in timecode mode, an extent (inclusive-end
length) is shown rather than a length.
Some objects, such as the TimeInfoBox, now deliberately shown an inclusive end
for their "end" clock, but this not universally followed, pending more feedback
from users and investigating of conventions in other DAWs.
Copyright-holder and year information is extracted from git log.
git history begins in 2005. So (C) from 1998..2005 is lost. Also some
(C) assignment of commits where the committer didn't use --author.
This functor/closure is responsible for stealing focus from any existing text entry (or whatever else may have focus)
when clicking on a CairoWidget or derived class.
The old implementation just gave focus back to the editor canvas. The new version walks up the widget packing
heirarchy to find a focusable parent (from the CairoWidget for which it is invoked). If no focusable parent
is found, it cancels keyboard focus in the toplevel window containing the CairoWidget
