Add domain name to backup file name

[GoogleCodeExporter]

The file created when executing "advanced, backup" does not include anything 
that identifies which server it was created from.

Adding the $_SERVER['HTTP_HOST'] variable to the downloaded file name helps.

/app/backup/index.php
original line #48:
                        $backup_file = 'backup_'.date('Ymd_His').'.'.$file_format;
proposed (tested, ok)
            $backup_file = $_SERVER['HTTP_HOST'].'-backup_'.date('Ymd_His').'.'.$file_format;

Also, the text on the backup page does not clearly define the 
default->backup->path variable does not exist by default and can have multiple 
paths separated by a space.
Since paths with spaces in their names are allowed in most O/Ss it should be a 
list that is delimited by something other than space.
Maybe the backup page should have the ability to modify that setting that is 
created at install?

Original issue reported on code.google.com by dddv...@gmail.com on 11 Jun 2015 at 12:44

[GoogleCodeExporter]

Hostname suggestion is okay.

A space is not a delimiter as we don't use delimiters for this feature nor do I 
see a need for one.

We have array type so there is no reason to use a delimiter to create a really 
long string that is harder to manage than an array.

This backup feature is taught in the FusionPBX -> Admin Class.

Original comment by markjcrane@gmail.com on 11 Jun 2015 at 4:41