Prettify kvm.sh output

* Modified kvm.sh list command to output tabular output identical to the output from the windows kvm.ps1 script
* Modified kvm.sh alias command to output tabular output identical to  the output from the windows kvm.ps1 script
* Fixed issue where package directory would be created when user tries to install non-existent package

This PR is based off of #363. I suggest you wait until that is merged before considering this PR.