Change location of header.php and footer.php

It is not possible to override header/footer via hooks in respective get_header()/get_header() functions.

However it is often overlooked that these function allow input and loading different headers.

For example get_header( 'nested/header' ); will look for header-nested/header.php in theme’s folder. It’s kind of a hack in regards to subdirectory use, but it works. 🙂