Indenting items in courses doesn't work in IE8 if you have AJAX and Javascript advanced features turned on for your profile.

The exact error in IE is:
User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C)
Timestamp: Tue, 14 Dec 2010 02:43:43 UTC

Message: 'classList' is null or not an object
Line: 54
Char: 1
Code: 0
URI: lib/javascript.php?file=%2Flib%2Fajax%2Fsection_classes.js&rev=184

Steps to replicate:
1) Set your profile's AJAX and Javascript setting to: 'Yes: use advanced web features'
2) Load up a course in IE8
3) Turn on course editing
4) Try and indent anything.

Expected Outcome:
The item would indent on the page without reloading.

Actual Outcome:
Javascript error occurs as above.

I believe the 'resource_class.prototype.indent_left' and 'resource_class.prototype.indent_right' functions in lib/ajax/section_classes.js need to be changed to not use classList in order to fix this.