VIVirtualMache.delete_snapshot_by_path does not return VITask

[GoogleCodeExporter]

The method delete_snapshot_by_path of VIVirtualMachine 
(https://code.google.com/p/pysphere/source/browse/trunk/pysphere/vi_virtual_mach
ine.py#930) is document to return a VITask when you run it async. In reality it 
always returns None because it doesn't return the return value of 
__delete_snapshot (which does the actual work).

Original issue reported on code.google.com by [email protected] on 9 May 2014 at 3:24