Important things here and in code flagged with XXX

0.20
	"Fix" multi-pseudo-STDOUT disabled in 09-open.t implementation?

	Alter tests to cover all invocation schemes,
	and document location of each in matrix?
		new/open each class
		scalar vs. glob vs. OO
		(non-)fully qualified subclass name

	Complicate IO::Pager::new code to make it smartly use first
	arg as FH or subclass and remove need for ungainly undef?

	"3-arg open" with layer?

0.10
	XXX Implement eof?
		To indicate SIGPIPE? ...handler localization difficulties (.16)

	Hijack something to return filehandle(?), child (DONE 0.24), etc.
	...but this amounts to nothing more than showing our private parts?
		Alas tied FH have no STAT method to pass child as inode (.16)
		Accessor for pager too? (.21)

0.02
	Implement IO::Pager::Callback, just because it sounds cool?
