add various EntryCompletion bindings
add various EntryCompletion bindings

* gtk_entry_completion_new()
* gtk_entry_completion_set_model()
* gtk_entry_completion_get_model()
* gtk_entry_completion_set_minimum_key_length()
* gtk_entry_completion_get_minimum_key_length()
* gtk_entry_completion_set_text_column()
* gtk_entry_completion_get_text_column()
* gtk_entry_completion_set_inline_completion()
* gtk_entry_completion_get_inline_completion()
* gtk_entry_completion_set_popup_completion()
* gtk_entry_completion_get_popup_completion()
* gtk_entry_completion_set_popup_set_width()
* gtk_entry_completion_get_popup_set_width()

gotk3/gotk3,gotk3/gotk3