Implement virDomain{Get,Set}Time APIs

While the setter can be generated automatically, the getter is not.
However, it would be a lot easier if they both share the same logic:
a python dictionary to represent the time: dict['seconds'] to
represent seconds, and dict['nseconds'] to represent nanoseconds.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

generator.py

@@ -519,6 +519,8 @@ skip_function = (
 
     'virDomainFSFreeze', # overridden in virDomain.py
     'virDomainFSThaw', # overridden in virDomain.py
+    'virDomainGetTime', # overridden in virDomain.py
+    'virDomainSetTime', # overridden in virDomain.py
 
     # 'Ref' functions have no use for bindings users.
     "virConnectRef",