Creates a new task in dialog

Edit lists activity now shows number of tasks
Deleting a task list deletes all related tasks

DoNExt/app/src/main/res/layout/new_task.xml

@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:padding="10dp"
     android:orientation="vertical"
     tools:context=".activities.MainActivity">
     <TextView
@@ -40,6 +41,7 @@
         android:text="@string/new_task_priority"
         android:textAppearance="?android:attr/textAppearanceLarge" />
     <RadioGroup
+        android:id="@+id/new_task_priority"
         android:layout_width="match_parent"
         android:layout_height="wrap_content">
         <RadioButton