PM message in e-mails

http://community.mybb.com/thread-137703.html
Recount Private Messages
PM message in e-mails

Applies the suggestion from @nmalcolm
Fixed Bug #2275

Corrected mismatched forum ID in moderator logs when sticking/closing thread on post
Improved URL validation

Although we don't check the supplied URL thoroughly, we should make sure that it _begins_ with either http:// or https:// instead of checking if it _contains_ http:// or https://.
Fixes #118.

Reference: https://archive.org/details/archive.org_bot
Fix issue with friendly redirects

Internal thread: http://community.mybb.com/thread-141783.html
Fixes #147
Preparing MyBB 1.6.12
Fixes #182 Group membership failure
Fixes #184 Changing Theme doesn't work
Remove incorrect sentence from language string

The page doesn't actually redirect the user. This area could be improved.
Remove <script> for popup_menu.js.

popup_menu.js no longer exists in 1.8.
Update JS cache breakers
Extra number formatting for attachment count
Initial focus upon opening modal
Remove index_loginform template.

This has been replaced with a modal.
Remove stray <br />

This was pushing the registration form down.
Add table header to latest news table.
Javascript consistency