Parses a file containing a [UI definition][XML-UI] and merges it with the current contents of @manager.
the name of the file to parse
Return: The merge id for the merged UI. The merge id can be used to unmerge the UI with gtk_ui_manager_remove_ui(). If an error occurred, the return value is 0.
GException on failure.
2.4
See Implementation
Parses a file containing a [UI definition][XML-UI] and merges it with the current contents of @manager.