As a user, I want to create a new discussion without changing page, so that I can create a discussion quickly and easily.

Behat tests provided. Prerequisites:  A course with a forum activity with optional subscription A student enrolled in the course. Testing Instructions: Case 1: Add discussion in-page, User forum auto-subscribe on. Log in as a student Go to your Forum preferences page under user preferences. Make sure " Forum auto-subscribe " is set to Yes. Go to the forum activity created. Confirm you can see the 'Add discussion' button. Confirm when you click it, a form appears below it with Subject and Message input field Fill in the form and click on the submit button. Confirm the page reloads and the newly entered discussion is displayed in the list Confirm that you are subscribed to the discussion. Case 2: Add discussion starting with in-page and then moving to advanced. Create another discussion. Fill out the Subject and Message fields. Click on " Advanced ". Confirm that you are redirected to the old post form. Confirm the subject and message content is populated with the contents from #2 Confirm that " Discussion subscription " is ticked. Submit the form and confirm the page reloads and the newly entered discussion is displayed in the list. Confirm that you are subscribed to the discussion. Case 3: Add discussion in-page, User forum auto-subscribe off. Go to your Forum preferences page under user preferences. Set " Forum auto-subscribe " is to No. Go to the forum activity. Click " Add discussion " Fill in the form and click on the submit button. Confirm the page reloads and the newly entered discussion is displayed in the list Confirm that you are NOT subscribed to the discussion. Case 3: Add discussion starting with in-page and then moving to advanced, User forum auto-subscribe off. Create another discussion. Fill out the Subject and Message fields. Click on " Advanced ". Confirm that you are redirected to the old post form. Confirm the subject and message content is populated with the contents from #2 Confirm that " Discussion subscription " is NOT ticked. Submit the form and confirm the page reloads and the newly entered discussion is displayed in the list. Confirm that you are NOT subscribed to the discussion.