Support nth-of-type pseudo-class selector

What new or enhanced feature are you proposing?

The :nth-of-type(an+b) pseudo-class notation represents an element that has
an+b-1 siblings with the same expanded element name before it in the
document tree, for a given zero or positive integer value of n, and has a
parent element. In other words, this matches the bth child of that type
after all the children of that type have been split into groups of a
elements each. 

What goal would this enhancement help you achieve?

Greater CSS Selectors Level 3 compliance.

For more information, see:
http://www.w3.org/TR/css3-selectors/#nth-last-child-pseudo

Original issue reported on code.google.com by azizatif on 14 May 2009 at 11:42

ltoussaint / fizzler

Support nth-of-type pseudo-class selector #28