virtual machine device interrogation sample

Demonstrates:
 * How to write python 2.7 and 3.3 compatible code in one script
 * How to parse arguments in a python script
 * How to pretty print format a dictionary
 * How to connect to a vSphere instance
 * How to search for virtual machines efficiently
 * How to interrogate virtual machine hardware info
 * How to determine the data type of a dynamic object instance
 * How to build a summary of a virtual device & virtual disk
 * How to interrogate a datastore and its hosts mounts

closes: https://github.com/vmware/pyvmomi-community-samples/issues/124
Merge pull request #125 from hartsock/issues/124

virtual machine device interrogation sample