Styles selector does not display in Drupal 4.7-HEAD

Similarly to bug #42128, the style selector is missing from the plugin_reg.php file.

Fix it by changing line 57 in plugin_reg.php

from:
$plugins['font']['theme_advanced_buttons1'] = array(fontselect', 'fontsizeselect');
or
$plugins['font']['theme_advanced_buttons1'] = array('formatselect', 'fontselect', 'fontsizeselect');

to:
$plugins['font']['theme_advanced_buttons1'] = array('formatselect', 'fontselect', 'fontsizeselect','styleselect');

PS: personally, I'ld add both to the 'default' group in line 39 instead of the 'font' group in line 57. The attributes in the 'font' group are evil, css-wise. However, since #42128 has already been committed, putting this fix in line 57 is more consistent. And who really cares, right? As long as they are there