Remove most of the "reply" buttons when a forum is set to "no indent"

[Aaron Wells]

As Nathan mentioned in https://reviews.mahara.org/3326, when you set a forum's indentation to "no indent", we still show a "reply" button next to each post. This is confusing, because there's no visible difference depending on which one you click "reply" to.

Basically, changing the indentation to "no indent" changes the behavior of the forum from threaded to single-thread. So we should reflect that. There should be a "post" or "reply" button at the top of the page and at the bottom, and your post should always be set as the reply to the current last post in the topic.

Perhaps we ought to change the text description of the "indent" setting as well, to reflect the fact that now it's about behavior as well as display?

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/3516

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/3516
Committed: http://gitorious.org/mahara/mahara/commit/e3f1cafa277068af4856ee6e806578413b999367
Submitter: Son Nguyen (<email address hidden>)
Branch: master

commit e3f1cafa277068af4856ee6e806578413b999367
Author: Robert Lyon <email address hidden>
Date: Mon Jul 28 15:37:49 2014 +1200

No indent forum style to only have two 'reply' buttons (Bug #1328388)

Instead of having reply buttons next to every post there are only
reply buttons before and after the list. The reply is saved as a child
of the latest existing post so the forum works in a chronological way.

Also added a help file to explain better what the indent options do.

Change-Id: I820a611670e0e1ef5e7a645497c0f223b773c2ae
Signed-off-by: Robert Lyon <email address hidden>