public static function getCorePath($alias, $core){
		return self::normalizePath(self::combinePath(self::getAliasPath($alias), $core));
	}
public static function getCorePath($alias, $core){
		return self::normalizePath(self::combinePath(self::getAliasPath($alias), $core));
	}
public static function getCorePath ( $ alias , $ core ) { return self :: normalizePath ( self :: combinePath ( self :: getAliasPath ( $ alias ) , $ core ) ) ; }
get core directory path
@param  string $alias the alias name
@param  string $core  core directory name
@return string        the root of core directory path
get core directory path