Fixed: aps installer bugs when using php7

Change string variables to array because they are treated as arrays later

See merge request !593

update databse - strict_mode compatible (https://www.howtoforge.com/community/th…

…reads/email-warning-after-modification-of-spam-level.76247/)

See merge request !586

update databse - strict_mode compatible (https://www.howtoforge.com/community/threads/email-warning-after-modification-of-spam-level.76247/)

fix onSubmit in mail_user_edit



See merge request !583

change password-defaults to pass https://mariadb.com/kb/en/mariadb/simple_password_check/



See merge request !581

Make AWstats default

Webalizer is pretty old and the latest release dates back to 2013.  
The generated statistics are even not really accurate, as mentioned here:  https://en.wikipedia.org/wiki/Webalizer#Criticism  

In conclusion I would appreciate it if the default value could be changed to AWstats.  
This merge request does address #3549

See merge request !577

Varios French translation improvements



See merge request !579

Make the webserver's rentention time for log files configurable

This feature ditches the current static 30 days approach of logfile purging and introduces a configurable retention time for each website.  
The retention time configuration can be found in the options tab of the website settings.  
  
  
  
Default retention time is the current 30 days value.  

However, by this approach it's possible to have retention times like 0 (forever), or very short retention times like 7 days which are often demanded by public/government data security officials which we have in germany.

See merge request !576

instead we are now using dynamic purging of the logs.