Refactored modules

src/task.rs

@@ -0,0 +1,20 @@
+pub type TaskId = String; // This is an HTML "etag"
+
+/// A to-do task
+#[derive(Clone, Debug)]
+pub struct Task {
+    id: TaskId,
+    name: String,
+    completed: bool,
+}
+
+impl Task {
+    pub fn id(&self) -> &TaskId     { &self.id          }
+    pub fn name(&self) -> &str      { &self.name        }
+    pub fn completed(&self) -> bool { self.completed    }
+
+    pub fn set_completed(&mut self) {
+        // TODO: either require a reference to the DataSource, so that it is aware
+        //       or change a flag here, and the DataSource will be able to check the flags of all its content (but then the Calendar should only give a reference/Arc, not a clone)
+    }
+}