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/libvirt-override-api.xml

@@ -162,6 +162,18 @@
       <arg name='domain' type='virDomainPtr' info='pointer to domain object'/>
       <arg name='params' type='virSchedParameterPtr' info='pointer to scheduler parameter objects'/>
     </function>
+    <function name='virDomainSetMemoryParameters' file='python'>
+      <info>Change the memory tunables</info>
+      <return type='int' info='-1 in case of error, 0 in case of success.'/>
+      <arg name='domain' type='virDomainPtr' info='pointer to domain object'/>
+      <arg name='params' type='virMemoryParameterPtr' info='pointer to memory tunable objects'/>
+    </function>
+    <function name='virDomainGetMemoryParameters' file='python'>
+      <info>Get the memory parameters, the @params array will be filled with the values.</info>
+      <return type='int' info='-1 in case of error, 0 in case of success.'/>
+      <arg name='domain' type='virDomainPtr' info='pointer to domain object'/>
+      <arg name='params' type='virMemoryParameterPtr' info='pointer to memory tunable objects'/>
+    </function>
     <function name='virConnectListStoragePools' file='python'>
       <info>list the storage pools, stores the pointers to the names in @names</info>
       <arg name='conn' type='virConnectPtr' info='pointer to the hypervisor connection'/>