Problem user email 1.8

Problem user email v1.8 changes:

Now compatible with XF 2.2 and newer.

Problem user email v1.7 changes:

Fixed issue where empty variable caused server error.

Problem user email v1.6 changes:

Fixed issue with selecting latest post.

Problem user email v1.5 changes:

Removed code which was no longer used. Updated Options page.

Problem user email v1.4 changes:

Fixed phrase which was not referenced properly.

Problem user email v1.3 changes:

Updated email templates.

Problem user email v1.2 changes:

Fixed problem when 'Threads' in options page.

Problem user email v1.1 changes:

Fixed variables in PHP file so correct templates are called.