Adding structure and defines for virDomainSet/GetMemoryParameters

This patch adds a structure virMemoryParameter, it contains the name of
the
parameter and the type of the parameter along with a union.

dv:
+ rename enums to VIR_DOMAIN_MEMORY_PARAM_*
+ remove some extraneous tabs

v4:
+ Add unsigned int flags to the public api for future extensions

v3:
+ Protoype for virDomainGetMemoryParameters and dummy python binding.

v2:
+ Includes dummy python bindings for the library to build cleanly.
+ Define string constants like "hard_limit", etc.
+ re-order this patch.

python/generator.py

@@ -306,6 +306,8 @@ skip_impl = (
     'virDomainGetSchedulerType',
     'virDomainGetSchedulerParameters',
     'virDomainSetSchedulerParameters',
+    'virDomainSetMemoryParameters',
+    'virDomainGetMemoryParameters',
     'virDomainGetVcpus',
     'virDomainPinVcpu',
     'virSecretGetValue',