"Create a new site" link at wp-admin/my-sites.php redirects to network homepage

[ebellempire]

WordPress Network blog creation link points to wp-signup.php.

BuddyPress redirects this link to the network homepage.

Suggested fix/enhancement:

add_filter('wp_signup_location', 'bp_blog_creation_link');
function bp_blog_creation_link($old) {
     return get_bloginfo('url').'/blogs/create/';
}

Wondering if we should revisit the whole redirect from wp-signup.php issue.

(In [5770]) Introduces bp-blogs-filters.php.
Introduces bp_blogs_creation_location(), to ensure that the 'Create a new blog' link at Dashboard > My Sites goes to the BP blogs creation URL.
Fixes #3941.
Props ebellempire for the initial patch.