remove mthr, now obsolete

contrib/mthr

@@ -1,46 +0,0 @@
-#!/bin/sh
-# mthr [-a|-s|-p] MSGS... - select thread/subthread/parent of messages
-
-mode=1
-case "$1" in
-	-a) mode=1; shift;;
-	-s) mode=2; shift;;
-	-p) mode=3; shift;;
-esac
-
-mseq : | awk -v mode=$mode '
-BEGIN { split("", parents) }
-NR != FNR { exit }
-{
-	match($0, "^ *")
-	ind = RLENGTH
-}
-mode==1 && ind==0 {
-	if (sel)
-		for (i in thread)
-			print thread[i]
-	split("", thread)
-	sel = 0
-}
-mode==1 { thread[length(thread)+1] = $0 }
-mode==2 && ind <= dep { sel = 0 }
-{
-	for (i in ARGV)
-		if (substr($0, ind+1) == ARGV[i]) {
-			sel = 1
-			dep = ind
-		}
-}
-mode==2 && sel { print }
-mode==3 && sel {
-	if (ind>0)
-		print parents[ind-1]
-	sel = 0
-}
-mode==3 {parents[ind] = $0 }
-END {
-	if (mode==1 && sel)
-		for (i in thread)
-			print thread[i]
-}
-' - $(mseq $@)