Melchior FRANZ:

Melchior FRANZ:

Vivian pointed out that a redefined Ctrl-U key binding didn't work
correctly. I found out that this is, because the definition in
$FG_ROOT/keyboard.xml sets <value type="bool"> for binding[1],
and ... [better sit down first!] ... and assigning <value type="double">
in a *-set.xml file doesn't *really* set "double" as new type!

Instead, the boolean is kept, and a double sqeezed into it. In other
words: once tainted as bool, you can throw all doubles in the universe
on a property node, and all it will accept is 0 and 1. Without warning!

BTW: I changed the patch: I was overly cautious: clear_value() does already
care for ties and for setting NONE, so we just need to make that public as
clearValue(), and use that. Makes the patch a bit more verbose, though.  :-/