vmware-iso: Fix error vnc min/max ports [GH-1288]
vmware-iso: Update VNCAddressFinder interface to return errors from VNCAddress()
vmware-iso/driver-esxi: Detect VNC in cross-platform way [GH-1372]

  Use VMware calls to determine ports being listened to, and determine
  free VNC port
vmware-iso/driver-esxi: Fix VNC detection of used ports

  Fixes error in earlier commit that didn't properly detect a port
  was listened to.
Merge pull request #1426 from jasonberanek/vnc-fixes

vmware-iso/esxi: fix multiple issues with VNC address discovery