Note to self: check to ensure this has been documented in Dev

+++ This bug was initially created as a clone of Bug #854369 +++

Description of problem:

It would be nice to have the option to retrieve system summary using engine-cli. 
We have this option in Rest API as well. 



Additional info:

<summary>
<vms><total>5</total><active>3</active></vms>
<hosts><total>2</total><active>2</active></hosts><
users><total>2</total><active>1</active></users>
<storage_domains><total>2</total><active>2</active></storage_domains>
</summary>

--- Additional comment from Michael Pasternak on 2013-03-12 06:35:15 EDT ---

[oVirt shell (connected)]# summary

hosts-active          : 0
hosts-total           : 4
storage_domains-active: 3
storage_domains-total : 4
users-active          : 1
users-total           : 3
vms-active            : 0
vms-total             : 7