Add priority feature

Now, todos have a priority flag.  When listed, these todos will be
bolded and italic.

You can list todos by priority by running `todolist l p`.

1 files changed, 14 insertions, 0 deletions

diff --git a/todolist/todo_list.go b/todolist/todo_list.go
index d7e1f83..71484c6 100644
--- a/todolist/todo_list.go
+++ b/todolist/todo_list.go
@@ -63,6 +63,20 @@ func (t *TodoList) IndexOf(todoToFind *Todo) int {
 	return -1
 }
 
+func (t *TodoList) Prioritize(id int) {
+	todo := t.FindById(id)
+	todo.IsPriority = true
+	t.Delete(id)
+	t.Data = append(t.Data, todo)
+}
+
+func (t *TodoList) Unprioritize(id int) {
+	todo := t.FindById(id)
+	todo.IsPriority = false
+	t.Delete(id)
+	t.Data = append(t.Data, todo)
+}
+
 type ByDate []*Todo
 
 func (a ByDate) Len() int      { return len(a) }