adding support for defaultPattern

Author: dmolsen

config/config.yml.default

@@ -37,3 +37,6 @@ cacheBusterOn: "true"
 exportDir: "export"
 publicDir: "public"
 sourceDir: "source"
+
+# defaultPattern to show on load
+defaultPattern: "all"

src/PatternLab/Config.php

@@ -235,6 +235,7 @@ public static function init($baseDir = "", $verbose = true) {
 		// which of these should be exposed in the front-end?
 		self::$options["exposedOptions"] = array();
 		self::setExposedOption("cacheBuster");
+		self::setExposedOption("defaultPattern");
 		self::setExposedOption("ishFontSize");
 		self::setExposedOption("ishMaximum");
 		self::setExposedOption("ishMinimum");