Add a large number of menu icons based on the Dashicons icon font. The icons are hidden by default, click the "More" button in the icon selector to display them. You can make them permanently visible by enabling the "Show more menu icons" setting in screen options.

Icon styles and associated metadata are generated based on /wp-includes/css/dashicons.css. 
To (re)generate the styles, go to: 
/wp-admin/options-general.php?page=menu_editor&sub_section=generate-menu-dashicons

Also adjusted the positioning of the icon selector drop-down from bottom-and-left to bottom-and-right to make it better fit the behaviour of native drop-down menus.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@861576 b8457f37-d9ea-0310-8a92-e5e31aec5664
Deny public access to the /includes directory. This is just a precaution; there have been no relevant vulnerabilities or other security issues reported so far.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@861579 b8457f37-d9ea-0310-8a92-e5e31aec5664
Switch from generating custom Dashicon CSS to passing "dashicon-whatever" to WP as the icon URL. Looks like I should've checked for documentation udpates before writing my own CSS generator :)

Minor: Don't try to display dashicons in older versions of WP.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@861721 b8457f37-d9ea-0310-8a92-e5e31aec5664