Add support for Dir-Less with html:not([dir='rtl'])

[manix84]

It'd be handy to add support for Dir-Less selection. This can be accomplished as simply as changing "html[dir='ltr']" to "html:not([dir='rtl'])". This would select all elements that aren't wrapped in a dir='rtl', and so, support more browsers.

[vkalinichev]

What's the point?

[dzearing]

If a user renders styles but does not provide the dir attribute, styles still render with this approach.

Currently if the attribute is omitted, your directionally sensitive properties won't even render.