[PATCH]Add option style argument to --demangle

[Ken Block]

A couple people did not like the --style switch. They felt the name was
too generic. So instead of adding a --style switch, I've added an
optional argument to "--demangle" and updated the documentation. I
posted this change as a suggestion before and nobody objected and one
person commented that they liked it, so I'd assume this is acceptable
and would appreciate if somebody could check this into CVS.