Add id's to fieldsets in wp-admin/profile.php

[Otto42]

Change this:

<fieldset>
<legend><?php _e('Update Your Password'); ?></legend>

to this:

<fieldset id='passwords'>
<legend><?php _e('Update Your Password'); ?></legend>

Reasoning: This would allow for a very simple plugin to do essentially the same thing that is given here:
​http://wordpress.com/blog/2007/06/07/how-strong-is-your-password/

All that would then be required of a plugin would be a hook to 'admin_head' to call wp_enqueue_script('jquery') and a hook to 'show_user_profile' to include the small amount of necessary html+javascript to do the password strength indicator.

Further suggestion: All fieldsets on profile.php should be given unique ID's.

(In [5689]) Add ID's to profile edit form's fieldsets. fixes #4434