Add the support to work with libvirt commit 66a85cb13.

Signed-off-by: Philipp Hahn <hahn@univention.de>

VIR_DOMAIN_EVENT_ID_IO_ERROR and VIR_DOMAIN_EVENT_ID_IO_ERROR_REASON
callbacks receive the same 'action' parameter, so also translate that
numeric action to a descriptive text for the first callback.

Signed-off-by: Philipp Hahn <hahn@univention.de>

ERROR_EVENTS translates the numeric 'action' argument to a description,
not the 'reason' argument which already contains a descriptive string
like 'enospc'.

> Traceback (most recent call last):
>   File "/usr/lib/python2.7/dist-packages/libvirt.py", line 4661, in _dispatchDomainEventIOErrorReasonCallback
>     reason, opaque)
>   File "libvirt-python/examples/event-test.py", line 536, in myDomainEventIOErrorReasonCallback
>     dom.name(), dom.ID(), srcpath, devalias, action, ERROR_EVENTS[reason]))
>   File "libvirt-python/examples/event-test.py", line 474, in __getitem__
>     data = self.args[item]
> TypeError: tuple indices must be integers, not str

Fixes: f5928c6711654f1496707ca77f626b3192843d57
Signed-off-by: Philipp Hahn <hahn@univention.de>

Closer to pep8

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>

to use new Description class

Signed-off-by: Philipp Hahn <hahn@univention.de>