Calls gtk_text_tag_table_lookup() on the buffer's tag table to get a GtkTextTag, then calls gtk_text_buffer_remove_tag().
name of a GtkTextTag
one bound of range to be untagged
other bound of range to be untagged
See Implementation
Calls gtk_text_tag_table_lookup() on the buffer's tag table to get a GtkTextTag, then calls gtk_text_buffer_remove_tag().