Tweak the Nav Menu UX, especially around menu creation.

props lessbloat, DrewAPicture, jkudish. fixes #23641

git-svn-id: http://core.svn.wordpress.org/trunk@23622 1a063a9b-81f0-0310-95a4-ce76da25c4cd
RTL for Nav Menu tweaks. see #23641. fixes #23645. props DrewAPicture.

git-svn-id: http://core.svn.wordpress.org/trunk@23623 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Add filters to comments_link_feed(), comment_link(), and get_comments_link(). esc_url() the echoed output of comments_link().

props MarcusPope.
fixes #19210.



git-svn-id: http://core.svn.wordpress.org/trunk@23624 1a063a9b-81f0-0310-95a4-ce76da25c4cd