Proposal: new "auto" value for the "direction" property

The current values of "rtl" and "ltr" for the "direction" property can 
produce unexpected results in situations where the content of an element 
can be either right-to-left or left-to-right text. See for example 
http://bugzilla.mozilla.org/show_bug.cgi?id=224685, especially comment 4.

For such situations it would be useful to have a value "auto", 
indicating that the direction depends on the intrinsic direction of the 
content. To determine the direction, the UA should use the algorithm 
described in rules P2 and P3 of the Unicode Bidi Algorithm at 
http://www.unicode.org/reports/tr9/#P2