scheduler channel/host grouping

[Matti Aarnio <mea@nic.funet.fi>]

Hello,

	I have experimented with a change at the scheduler selector matching
	code -- at first I thought the system did have it already, but no,
	I had to add them myself.

	Essentially the selector works in style of SH {xx,xx,xx} patterns,
	although it is a bit more limited.  It is applicable only at the end
	of the pattern, and nothing can follow it:

		smtp/*.{cn,kr,tw,id,in,hk}
		smtp/*.{nl,be,lu,at,ch}

	That is, following will not work:
		smtp/*.{edu,ed,ac}.??
	(to match all academic sites in several countries with this pattern)

	My initial dismay was my unability to group target toplevels with
	less load together, and thus I coded this.

	I will shortly go off the net for a short vacation, but I shall be
	back by next monday (14th July).

	I will try to make an experimental patch5 available at my workstation
	(ftp://mea.tmt.tele.fi/)

/Matti Aarnio <mea@nic.funet.fi>