Implemented: FS#951 - Dashboard module

fix bug FS#1200 - id elents should be unique. have changed side nav template, this needs to change too.

and
give nav list items unique ids (requires nav.css be changed too!)

Added new theme. You now can change between 64px size icons, 32px size icons (the default-value) and no icons

Added a new module called "domain". With this module you can manage all domains (web + mail). Per default this module is not active. To activate it, you have to change the System Interface Config -> domains -> use the domain module. You also have to activate the domain-module for the admin (and for every client if you want). Important: you can not use this module if you have reseller!

Fixed: FS#655 - Resolution problem 12024x768 Px in Backend