1.9.9 WordPress phpBB integration

== Changelog ==

= 1.9.9 =
*Release Date - 5 Dic, 2019*
* Security patch: see https://www.axew3.com/w3/forums/viewtopic.php?f=2&t=1432
* Add: Security patch -> random 20/32 string length to increase security
* Fix: Correctly connect to another database port if it is required by phpBB
* Add: display error message into plugin admin page, if (until) phpBB db connection fail, and set integration as NOT LINKED USERS in the while, to avoid configuration problems
* Add: Shortcode w3allphpbbupm for phpBB users PM notification in WordPress: https://www.axew3.com/w3/2019/12/shortcode-phpbb-pm-into-wordpress/
* Add: unique query into main verify_phpbb_credentials() to retrieve any phpBB user's Group permissions (become active only when mchat option active, since these kind of data are useful at moment only in this contest)
* Update all iframe resizer files to last version, update page-forum.php callback to last related code and iframe v4 code
* iframe code v4 procedure here:
* Minor fixes and code/inline comments cleanup

Update time! 1.9.9 WordPress phpBB integration has been released!