Unmaintained Change "Post New Thread" Button (per forum) 1.0

Re-factored code to use the xf_forum table instead of xf_node so it only gets applied to forum nodes, not all nodes.

Added code into installer to remove old field in xf_node and create new field in xf_forum.

Note:

1. You will need to re-edit any forum nodes you have already applied this to (sorry!)
2. You can remove this file, it's no longer required: /library/NewThreadButtonText/DataWriter/Node.php

Quick update to add a missing template modification.

~No need to upload files, just import the XML

This update ensures that the "Post New Thread" page title, on thread create pages are also altered.

Fixes a bug when adding or editing non forum node types