Removed echo.groovy from Quickstart example

The Quickstart is now using the new echo.mapper. This mapper is echoing the requisition. The script step with the echo.groovy file is repaced.
Splitting documentation and introduced sidebar for navigation
Added VMware Host System source
- PRIS-22: Created simple VMware source which provides a requisition
           of ESX host systems and assigns, categories and asset
           fields with services like VMware-ManagedEntity and
           VMware-HostSystem
- PRIS-23: Started implmentation of VMware source which provides a
           requisition of virtual machines, categories and asset
           fields with services like VMware-ManagedEntity and
           VMware-VirtualMachine are assigne. The mapping for the
           management VMware instance is not assigned to virtual
           machines yet.
- Refactoring and removed dead code. There is one uncommented code
  for getting IP interfaces from virtual machines. It is currently
  not clear if the method getting just the VMware Tools provided
  IP-Address is correct.