Twenty Fifteen: improve naming and documentation of customizer js files to match core filenaming conventions.

Props celloexpressions, fixes #30160.


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Twenty Fifteen: adding help text to explain how color changes to header and sidebar are affected by responsive design.

Props iamtakashi, iandstewart, fixes #30165.


Built from https://develop.svn.wordpress.org/trunk@30272


git-svn-id: http://core.svn.wordpress.org/trunk@30272 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Twenty Fifteen: Removing email obfuscation from social links menu.

We really should be doing this in all menus, at which point this becomes core or plugin functionality, not a theme feature.

Closes #30214.


Built from https://develop.svn.wordpress.org/trunk@30273


git-svn-id: http://core.svn.wordpress.org/trunk@30273 1a063a9b-81f0-0310-95a4-ce76da25c4cd