rc: prepare for PHP 5.6 and remove pre-5.5 compat

etc/rc.php_ini_setup

@@ -29,12 +29,15 @@
 PLATFORM=`/bin/cat /etc/platform`
 MIN_REALMEM_FOR_APC=512
 
-if [ -d /usr/local/lib/php/20121212 ]; then
+if [ -d /usr/local/lib/php/20131226 ]; then
+	# PHP 5.6
+	EXTENSIONSDIR="/usr/local/lib/php/20131226/"
+elif [ -d /usr/local/lib/php/20121212 ]; then
+	# PHP 5.5
 	EXTENSIONSDIR="/usr/local/lib/php/20121212/"
-elif [ -d /usr/local/lib/php/20090626 ]; then
-	EXTENSIONSDIR="/usr/local/lib/php/20090626/"
 else
-	EXTENSIONSDIR="/usr/local/lib/php/20060613/"
+	echo "No supported PHP version was found."
+	exit 1
 fi
 
 # Grab amount of memory that is detected