allow sig to generate signatures for functions that are not 100%
pure ascii

Reference: /n/atom/patch/applied2013/sigrune
Date: Thu Dec  5 13:40:18 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /rc/bin/sig	Thu Dec  5 13:39:17 2013
+++ /rc/bin/sig	Thu Dec  5 13:39:17 2013
@@ -3,7 +3,7 @@
 #	prints out function signatures by grepping the manual
 
 
-*=`{echo $*|tr A-Z a-z|tr -dc 'a-z0-9_ \012'}	# fold case, delete funny chars
+*=`{echo $*|rune/case|tr -dc 'a-z0-9_. \012 -􏿿'}	# fold case, delete funny chars
 if(~ $#* 0){
 	echo Usage: sig function ... >/fd/2
 	exit 1