[tei-council] idno -> ptr

[Syd Bauman]

OK. Changes checked in (at rev 12293). I've closed 448, too. However,
the stylesheets don't render a <ptr> in the middle of a bibliographic
citation all that well.

I don't know if it's ugly enough to permit being fixed during this
week of "pre-release code freeze" or not. James?

> That's right. The <idno>s are currently children of <biblStruct>,
> but per https://sourceforge.net/p/tei/bugs/448/ , we need to move
> these to be children of <analytic>, <monogr>, or <series>.