Provide a way to customize taxonomy terms when generating sitemap from taxonomy tree

Hi all,

Problem/Motivation

I found that in current version of the module 6.x 2.2 it is impossible to alter or theme taxonomy terms rendered in _site_map_taxonomy_tree function by for example weight of the term. It will be nice if we will have a way to wrap root term for example in h3, terms with depth == 1 with h4 ... In sites where in the list we do have 5 or more depth levels and 1000+ term items rendered is this almost a necessary.

Proposed resolution

I made a patch that creates 2 new alter hook callbacks 1st one [site_map_term_item_class_alter] called before rendering the li of the term item and 2nd [site_map_term_item] called before appending the term item to the output. This way we can alter css classes and html of the rendered taxonomy tree that can be used for better styling and leads in overall better readability of the rendered taxonomy tree.

There is a way to analyze this issue in more depth to provide more ways of altering but I found the 2 hooks to fulfill my requiremends.

Thank you