Function to change path field

[wpmuguru]

MU Trac Ticket: ​http://trac.mu.wordpress.org/ticket/1061

I've been working on a code where I need to modify the value of the path field of a blog. The problem is that, although there are functions that updates this value on the blog table, there isn't any function to change this path inside the wp_blog table of the database. I've made a function that changes this field in both wp_blog and wp_??_blog tables, which you can see in the attached patch.

In MU the blog path can be changed in the site admin -> blogs screen. It can also be done using a couple queries with $wpdb. On the 80/20 scale, this is a 20.