Patch unsupported shortcode tags for WordPress 4.4

shortcodes.php.patch

add_filter('the_content', function($content){
	global $shortcode_tags;

	$tagnames = array_keys($shortcode_tags);
	$tagregexp = join( '|', array_map('preg_quote', $tagnames) );

	// Convert [tagname="mainproperty" to [tagname "mainproperty" (still accessible by $atts[0])
	$content = preg_replace("/\\[($tagregexp)=/s", '[$1 ', $content);

	return $content;
}, 0);