filter RNA classes for translation (removes over 1300 lines from messages.txt)

- omit operators tagged as INTERNAL
- omit classes  for internal use: Event, Context, Property, Function, Window.

release/scripts/modules/bpy/ops.py

@@ -27,6 +27,7 @@ op_poll = ops_module.poll
 op_call = ops_module.call
 op_as_string = ops_module.as_string
 op_get_rna = ops_module.get_rna
+op_get_instance = ops_module.get_instance
 
 
 class BPyOps(object):
@@ -184,11 +185,13 @@ class BPyOpsSubModOp(object):
         return ret
 
     def get_rna(self):
-        '''
-        currently only used for 'bl_rna'
-        '''
+        """Internal function for introspection"""
         return op_get_rna(self.idname())
 
+    def get_instance(self):
+        """Internal function for introspection"""
+        return op_get_instance(self.idname())
+
     def __repr__(self):  # useful display, repr(op)
         import bpy
         idname = self.idname()