Added inserting node to index for myhtml_tree_node_insert_by_node function; https://github.com/lexborisov/myhtml/issues/66#issuecomment-247941324
Added inserting node to index for myhtml_tree_node_insert_by_node function; https://github.com/lexborisov/myhtml/issues/66#issuecomment-247941324

layershifter/myhtml,layershifter/myhtml,lexborisov/myhtml,lexborisov/myhtml