[Liam W.] Thread Solutions 2.4.3 Fix 1

This add-on allows your users to mark a thread as 'solved' by choosing a post as a solution. These posts are given markup, to make them more obvious, and a link at the top of the thread allows the user to be taken directly to the solution.

Multiple solutions per thread are allowed, allowing more than one person to be appreciated for giving a resolving answer.