Specifying multi-domain jails in Gollem FTP

Not exactly documented, most people may assume that setting an FTP jail is restricted to absolute paths in Gollem's backend.php .

This is clearly not suitable for servers where users log into virtual sites under different domains. Two styles of jails are then desired:

1. The user is restricted to /path/to/site-root/home/user
   1. The user is restricted to /path/to/site-root (suitable for site owners)

Trouble is, the site-root location is a variable.

Turns out the backend processing can in fact handle the required shorthand, and one can specify jail root relative user home.

Thus, the following achieves the goal of (2)

'root' => '~/../..',

'home' => '~',

The undocumented part is that setting 'root' requires that 'home' also be specified (Gollem v1).