Implements __str__ and __repr__ method for PyMI objects
Implements __str__ and __repr__ method for PyMI objects

Currently, PyMI debugging using PyMI can be a bit difficult,
when compared to the old WMI.

For example, the old WMI has an object string representation
implementation, meaning that WMI objects can easily and
usefully be printed, while PyMI doesn't:

    >>> print new_wmi.Msvm_VirtualSystemSettingData()[0]
    <wmi._Instance object at 0x0000000002E45CC0>

This patch adds a similar __str__ and __repr__ implementation to PyMI.

cloudbase/PyMI,cloudbase/PyMI,cloudbase/PyMI