use wp_register() in wp-login.php

[linuxarchitect]

wp_register() calls a filter to change the registration link, but wp-login.php still has the link hardcoded to the default link.

patch to implement enhancement request

For logged in users, this would display "Site Admin" link instead of "Register". Some things to consider:

1. It seems less consistent with "Lost your password?" link.
2. To register a new user, or to simply review the registration screen, site administrator would have to log out first.

The patch needs refresh due to [19027].

Duplicate: #19097

Related: #17950

refreshed patch to 3.5