recent change to keyframe menu broke BVH import, now don't use the operator at all, instead assign the action manually.

Also added bpy.path.display_name_from_filepath(), since filepaths are not ensured to be utf8.
same as calling:  os.path.splitext(os.path.basename(name))[0].encode("utf8", "replace").decode("utf8")

release/scripts/modules/bpy/path.py

@@ -110,6 +110,13 @@ def display_name(name):
         return name_base
 
 
+def display_name_from_filepath(name):
+    """
+    Returns the path stripped of directort and extension, ensured to be utf8 compatible.
+    """
+    return _os.path.splitext(_os.path.basename(name))[0].encode("utf8", "replace").decode("utf8")
+
+
 def resolve_ncase(path):
     """
     Resolve a case insensitive path on a case sensitive system,