Without this patch, no actual API calls are being made through the Fog
layer to the underlying rbvmobi later and ultimately to the vSphere
target API.
This patch adds a simple current_time request which is similar to a
"ping" The layers and API are exercised fully using this simple API
call to retrieve the current time on the remote system.
This provides:
>> Fog::Compute[:vsphere].current_time
Tue Aug 30 20:46:27 UTC 2011
>> Fog::Compute[:vsphere].requests
[:current_time]
