Push menu settings checkboxes down to a new line to avoid weird overlaps in some languages.

props SergeyBiryukov. see #24546.

git-svn-id: http://core.svn.wordpress.org/trunk@24566 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Recombine a fragmented help paragraph so its integrity does not depend on translaters noticing a trailing space in the first sentence.

props xibe. fixes #24546.

git-svn-id: http://core.svn.wordpress.org/trunk@24567 1a063a9b-81f0-0310-95a4-ce76da25c4cd