Simplify hidden HTML and avoid its detection as malware

Fix some scenarios where ^userpoints records are not present and generate issues

Fixes for MySQL 5.7 IGNORE_SPACE option

Total questions unanswered lang file

Adding total questions unanswered to Admin Stats

https://github.com/q2a/question2answer/pull/598

Clarified the description regarding shared users

https://github.com/q2a/question2answer/issues/595

Many random tweaks

Fix qa_get_gravatar_url() function not found when using WordPress

Paste/Paste isn't working in ckEditor

Solves issue where __autoload cannot be used on PHP 7.2.

Cache files now use PHP to avoid being readable. We also prevent access with .htaccess (for the common Apache setup).

Load process modules as early as possible for after_db_init plugins

Updated htmLawed to v1.2.4.1 - 12 September 2017.

Fixes #575