Run .todo.actions.d Before Builtins

.
Let users override default commands by creating a script in
~/.todo.actions.d/ with the same name as a default command.  Idea by Don
Harper and David A. Harding; patch by Harding.
.
The patch adds the following logic and increases the indent level for
the case statement:
.
+if [ -d "$HOME/.todo.actions.d" -a -x "$HOME/.todo.actions.d/$action" ]
+then
+    CFG_FILE="$CFG_FILE" "$HOME/.todo.actions.d/$action" "$@"
+else
+    case $action in

todo.sh

@@ -332,6 +332,10 @@ shopt -s extglob
 # == HANDLE ACTION ==
 action=$( printf "%s\n" "$1" | tr 'A-Z' 'a-z' )
 
+if [ -d "$HOME/.todo.actions.d" -a -x "$HOME/.todo.actions.d/$action" ]
+then
+    CFG_FILE="$CFG_FILE" "$HOME/.todo.actions.d/$action" "$@"
+else
     case $action in
     "add" | "a")
 	if [[ -z "$2" && $FORCE = 0 ]]; then
@@ -744,13 +748,6 @@ note:  PRIORITY must be anywhere from A to Z."
 
     * )
 	usage
-    if [ -d "$HOME/.todo.actions.d" ]; then
+	;;
-        if [ -x "$HOME/.todo.actions.d/$action" ]; then
-            CFG_FILE="$CFG_FILE" "$HOME/.todo.actions.d/$action" "$@"
-        else
-            usage
-        fi
-    else
-        usage
-    fi
     esac
+fi