[IE8] element.html test fails in various places

[Tobiasz Cudnik]

Depending on chosen mode on IE8, element.html test fails in various places. ​This patch seems to fix it, but it uses too many workarounds and need to be rewritten. It should use less workarounds as possible, mostly on IE8 strict.

[Garry Yao]

The correct fix would fall into setAttribute/removeAttribute, and addClass/removeClass just use the former under the hood.

[Garry Yao]

There's still a minor problem for 'test_setAttribute2, test_setAttributes, test_getAttribute_ignoreExpandoAttributes' to pass on IE8 strict because of style text formatting problem:

*Expected:

float: right;

*Actual:

FLOAT:RIGHT

But as discussed with Tobias, we'll open a new ticket for this.

[Tobiasz Cudnik]

Issue mentioned by Garry has been moved to #3693.

This issue is fixed with [3644].