Had to add back the check for VM status in virsh list parsing because if there were no VMs there would be some errors causing the recipe to exit prematurely.

This change also moves the yum remove of eucalyptus* packages to an execute command rather than use yum_package. Yum_package did not like wildcard character for package names.
Add upgrade recipe.  To use it supply eucalyptus and euca2ools repo to upgrade to.
example upgrade.json:

{
    "eucalyptus": {
      "yum-options": "--nogpg",
      "eucalyptus-repo": "http://packages.release.eucalyptus-systems.com/yum/builds/eucalyptus/branch/maint-3.4-testing/centos/6/x86_64/",
      "euca2ools-repo": "http://packages.release.eucalyptus-systems.com/yum/builds/euca2ools/commit/fd0d10fd240dd04616bdc303b71687dda673bc71-2014-01-23-001/centos/6/x86_64/"
    },
    "run_list": [
    	"recipe[eucalyptus::upgrade]"
    ]
}

This change also moves from using exec command to stop/start services to use chef's service API
Merge remote-tracking branch 'upstream/master'
Merge pull request #3 from tbeckham/master

Clean up nuke recipe and add upgrade recipe