window-min-height documentation

[Allotrope Petrofsky]

In GNU Emacs 21.1.1,

Window-min-height and window-min-width should be mentioned in the doc
strings for split-window{,-horizontally,-vertically} and in the info
nodes (emacs) Split Window and (elisp) Splitting Windows.

The Splitting Windows node should also state whether the absolute
minimum has been changed from 2 to 3 because of header-lines or from 2
to 1 because mode-lines are now optional.  The implementation should
be fixed to match.

I vote for the latter option.  See the "core dump when window is too
short" thread.

-al