Fixed a bug that prevented the modification of website settings of a site that the user created.

- The home directory of a shell user gets deleted when the user is deleted.

- FS#501 - disable shell account untill jailkit is finished 

- Improved installer and updater for multiserver mode. Modules and plugins were only configured if the selected service is available on the server.

Fixed a bug in ssh user plugin which resulted in a change of the shell to /bin/bash when a user was updated even when jailkit was enabled.

Added chroot options to the shell user form
Added jailkit ini settings
Added ini settings for fastcgi
Fixed bug with web delete not removing parent web user unless that was intentional ?
Changed name of shell user plugin so plugin order calls this first
Started a change to the update script.

TODO: Fix problem with jailkit chroot users logging into parent web user's directory. Fixup bash command prompt to display the correct user somehow because they all share the same id. 

Fixup install / update script so the fastcgi script and directory is created for the ispconfig site on setup / update. Can't work out how to get to the templating system to generate the script from. 

Moved server modules and plugins to new directory and updated the installer to create the symlinks for the modules and plugins from *-available to *-enabled directory.
Fixed a typo in mailfilter template.

Updated apache ssl cert creation.