Bug Fix: Issue 6 append and replace unexpected behavior if there's an & in task (even in quotes)

Using the cleaninput function, to escape &'s on certain actions.
Currently the actions needing escaped &'s are append, prepend and replace.
Other actions including add need unescaped &'s.

tests/t1400-prepend.sh

@@ -52,4 +52,9 @@ TODO: 3 of 3 tasks shown from $HOME/todo.txt
 
 EOF
 
+test_todo_session 'prepend with &' <<EOF
+>>> todo.sh prepend 3 "no running & jumping now"
+3: no running & jumping now stop
+EOF
+
 test_done