Implemented #4271 Creating vHost Website Alias copies default index.html thus breaking the original site if it's based on index.php (or something not index.html)

MLMMJ - Membership management

I think I'm close to the end of major works on this plugin...
I've implemented an interface to get simple list configuration, but using a lot of MLMMJ "TUNABLES". Anyway, there are a lot of unmanaged tunable yet. I wish to receive some feedbacks about what and how implement these. 
About the membership management: for now there is a minimal form, containing only list, name and mail of desired member. 

I think that from now, there will be a concrete (and better) alternative to mailman. I can improve a lot the whole system, but I think to be on the right way...what do you think about it?

See merge request !473

Update language_edit.htm: add col-sm-3 to label-tag so that the language key is …

…on the left side instead of the right side with all other keys.

See merge request !474

Update language_edit.htm: add col-sm-3 to label-tag so that the language key is on the left side instead of the right side with all other keys.

XMPP Server Setup bugfix for 3.1

Content:
- replaced old dev default values in dns generation for XMPP domains by server name
- added datalog tokens for xmpp domains and users
- fixed DB query for XMPP authentication and user query
- added default values for all CSR fields, so they cannot be empty

There is still a new error with the authentication. The Auth script used to authenticate against the database should be spawned in its own process, but the auth module seems not to load it.  
Maybe it is a problem with new library versions released during the last year. I'm in contact with the metronome Devs to solve this problem.

In meantime, this bugfix will ensure that the servers are configured correctly.

See merge request !471

Fixes: 3878 + ipv6-prefix for mirror



See merge request !472

Adding client information to database user list (additional question on #4264 fixes #4264)



See merge request !469

Fixes: #4264



See merge request !468

Wrong list defined in FTP stats (fixes #4267)



See merge request !467

Create/Delete Secondary DNS with remote API #4242

i just added a proposed code on howtoforge
https://www.howtoforge.com/community/threads/create-delete-secondary-dns-with-remote-api.74136/

See merge request !460

Fixed: Call to a member function fault() on null



See merge request !466