slay: kill processes via egrep(1) regex matching.

Usage:
	slay [-s #] [-#|-SIG] [-w #] [-nr] <regex>";

	-s #	set signal number (default: -KILL)
	-#	same as -s #
	-SIG	e.g. -HUP, -TERM, ...

	-nr	No reply: "y" is assumed.
	-w #	wait # seconds between each process (-nr mode only).

	--	means end of switches.

Notes:
	Unless -nr is supplied, you are prompted with [y]/n
	whether to kill each matching process.

	If stdin is redirected from, say, /dev/null, all prompt
	responses will be "y" (i.e. the default)

	The ps(1) command is: ps wax | egrep ...