Add option -? for usage to non-Windows version of dotty

diff --git a/cmd/dotty/dotty.sh b/cmd/dotty/dotty.sh
index b3789567df7d5bdab2de22240f6e0ce552652822..86ed4c8b5c76aad47ed7eed56be4579875bea13a 100755 (executable)
--- a/cmd/dotty/dotty.sh
+++ b/cmd/dotty/dotty.sh
@@ -45,6 +45,10 @@ while [ "x$1" != 'x' ]; do
         FILES=`echo $FILES \"$1\"`
         shift
         ;;
+    -\?)
+        $usage
+        exit 0
+        ;;
     -*)
         $usage
         exit 1