Fix missing error constants in libvirt python module

The previous change to the generator, changed too much - only
the functions are in 'virerror.c', the constants remained in
'virerror.h' which could not be renamed for API compat reasons.

Add a test case to sanity check the generated python bindings

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

sanitytest.py

@@ -0,0 +1,31 @@
+#!/usr/bin/python
+
+import libvirt
+
+globals = dir(libvirt)
+
+# Sanity test that the generator hasn't gone wrong
+
+# Look for core classes
+assert("virConnect" in globals)
+assert("virDomain" in globals)
+assert("virDomainSnapshot" in globals)
+assert("virInterface" in globals)
+assert("virNWFilter" in globals)
+assert("virNodeDevice" in globals)
+assert("virNetwork" in globals)
+assert("virSecret" in globals)
+assert("virStoragePool" in globals)
+assert("virStorageVol" in globals)
+assert("virStream" in globals)
+assert("VIR_CONNECT_RO" in globals)
+
+# Error related bits
+assert("libvirtError" in globals)
+assert("VIR_ERR_AUTH_FAILED" in globals)
+assert("virGetLastError" in globals)
+
+# Some misc methods
+assert("virInitialize" in globals)
+assert("virEventAddHandle" in globals)
+assert("virEventRegisterDefaultImpl" in globals)