allow "." as a legitimate character.  e.g. "lookman plan9.ini" or 
lookman "venti.conf".

Reference: /n/sources/patch/applied/lookman-dot
Date: Tue Aug  7 03:56:18 CES 2007
Signed-off-by: quanstro@quanstro.net

--- /rc/bin/lookman	Tue Aug  7 03:55:28 2007
+++ /rc/bin/lookman	Tue Aug  7 03:55:27 2007
@@ -8,7 +8,7 @@
 	rm -f $t1 $t2
 	exit 1
 }
-*=`{echo $*|tr A-Z a-z|tr -dc 'a-z0-9_ \012'}	# fold case, delete funny chars
+*=`{echo $*|tr A-Z a-z|tr -dc '.a-z0-9_ \012'}	# fold case, delete funny chars
 if(~ $#* 0){
 	echo Usage: lookman key ... >/fd/2
 	exit 1