acme: add -m option and avoid looking in the mirror
diff --git a/src/cmd/acme/look.c b/src/cmd/acme/look.c
index 66c6c66..2ca2061 100644
--- a/src/cmd/acme/look.c
+++ b/src/cmd/acme/look.c
@@ -620,7 +620,7 @@
 	if(w != nil)
 		goto Isfile;
 	/* if it's the name of a file, it's a file */
-	if(access(e->bname, 0) < 0){
+	if(ismtpt(e->bname) || access(e->bname, 0) < 0){
 		free(e->bname);
 		e->bname = nil;
 		goto Isntfile;