Adding bbcodes via accesskeys on IE drops selection

On browsers other than IE, when pressing an accesskey to insert a bbcode with some text selected, bbcode is inserted around the text and the text continues to be selected such that additional bbcodes can be inserted.

On IE, bbcode is now inserted correctly (http://tracker.phpbb.com/browse/PHPBB3-8996) but the selection is cleared and cursor is placed after the closing bbcode tag.

https://github.com/phpbb/phpbb3/pull/448 had an attempt at making it work but was incomplete. There is a large number of pages on the internets dealing with selections, ranges and IE that might present a solution.

On IE6, if there is a selection and bbcode is applied by mouse clicking the bbcode button, the entire bbcode and its contents appear to be selected, however applying more bbcodes just appends them to the end of the selection instead of wrapping the selection. If with the selection selected I press an ordinary letter the entire selection is replaced with the letter.