Issue title: Minor Install Packages to Add to Ubuntu Apt 
 Issue body: qemu-utils (to get qemu-img) and xtightvncviewer should be apt prereqs. 
 Comments: 
 Comment 0: Hi, 

Thanks for message.

* xtightvncviewer is not require because by default you should have vinagre
* qemu-utils: It's not mandatory to use GNS3 even if usefull. But most user will not use it.
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