Changing fret-diagram muted string symbol

[José Luis Cruz]

Hello,

I've searched in manual and in the list archive, but i've been able to
find a way for substituting the 'x' symbol that denotes a muted string
in a fret-diagram.

I want to be able to use another symbol, like a blank space, or
ideally a markup (for changing font's size and attributes).

If someone is so smart for figuring a way, maybe we're lucky and it
can be applied also to substitute any dot inside the fret-diagram for
another symbol? :-)


cheers.