improved nginx http to https redirect

"if" constructions in nginx should be used only if no other solution is possible, because "if" is the slowest directive and adds performance penalties (["If is Evil"](https://www.nginx.com/resources/wiki/start/topics/depth/ifisevil/)). This merge request is supposed to improve this issue and adds another "server" block instead of using "if" directive. This is a "standard" approach which is widely used in nginx configurations for http->https redirections. All other functionality and features of ISPConfig are preserved.

Closes #2209 (redirection without "if" directive)
Closes #3118 (the "split" is achieved using "server" blocks without "if" directive)

See merge request !578

added support for sql flags

this adds support for MySQL SSL encryption between servers in multiserver setup

See merge request !573

RewriteRule ^ %{REQUEST_URI} is faster than ^(.*)$ $1



See merge request !562

Fix #4601 Rewrite HTTP to HTTPS subdomain problem

This resolve:
On fast-cgi and php-fpm (maybe the others configurations too) subdomain redirection from http to https.

I opened a bug on: #4601

See merge request !565

cancel to right location dns records

when one is going to add a dns record and pushes the cancel button, it returns to the **DNS Zone** tab instead of **Records**

See merge request !572

vlogger for more precise stats with %O for apache >=2.5

this provides a more accurate traffic statistic, since also includes the amount of bytes received according to [apache doc](https://httpd.apache.org/docs/trunk/mod/mod_logio.html)

i could not make work version >= 2.4.7, so i opted to use this for version >= 2.5

See merge request !571

stretch added



See merge request !568

create directories for letsencrypt



See merge request !569

mkdir for letsencrypt

this folder is needed by **file_put_contents** when **.well-known** is clean

See merge request !567

added setting

this setting is needed for FTP traffic stats

See merge request !566

Fix for Issue #4363 - dns_templatezone_add not working

This fixes Issue #4363.

'xfer' column can not be NULL in dns_soa table. Same solution is used in interface/web/dns/dns_wizard.php file.

It also returns created dns soa id - without return value SOAPpy would fail with "SAXParseException: <unknown>:1:0: no element found". All other functions I checked do return a value.

See merge request !564

added -l to umount commands

the log folder is not deleted, because the **umount** command needs to be lazy, that's why we added the **-l** argument.

```
Tue Mar 21 23:59:01 UTC 2017 umount: /home/0/57/log: target is busy
Tue Mar 21 23:59:01 UTC 2017 (In some cases useful info about processes that
Tue Mar 21 23:59:01 UTC 2017 use the device is found by lsof(8) or fuser(1).)
Tue Mar 21 23:59:01 UTC 2017 rm: cannot remove '/home/0/57/log': Device or resource busy
```

See merge request !561

Debian stretch



See merge request !563

Added possibility to set new aps to disabled by default 2

Update for !552

See merge request !558

context corrected



See merge request !560

fixes dontlog vulnerability

this fixes #4585

See merge request !559

This reverts commit dbec32fa