Implements Config and Logging plugins, tidies Main

Added Database and Flatfile plugin engines for both Config and Log classes.
Rewrote Main to make use of the new plugins.
Updated config file definitions to make use of plugins.

source/lib/Sihnon/Config.class.php

@@ -31,25 +31,13 @@ class Sihnon_Config {
      * @var array(string)
      */
     const TYPE_STRING_LIST = 'array(string)';
-
-    /**
-     * Contents of the dbconfig file 
-     * @var string
-     */
-    private $dbconfig;
     
     /**
-     * Database object created for the lifetime of this script
-     * @var Sihnon_Database
+     * Backend to be used for this Config object
+     * @var Sihnon_Config_IPlugin
      */
-    private $database;
+    private $backend;
 
-    /**
-     * Associative array of connection parameters for the database configuration
-     * @var array(string=>string)
-     */
-    private $databaseConfig = array();
-    
     /**
      * Associative array of settings loaded from the database
      * @var array(string=>array(string=>string))
@@ -59,56 +47,13 @@ class Sihnon_Config {
     /**
      * Constructs a new instance of the Config class
      *
-     * @param string $dbconfig Database configuration file contents
+     * @param string $backend Backend to use for storing and retrieving configuration items
+     * @param mixed $options Parameters to configure the Config backend
      * @return Sihnon_Config
      */
-    public function __construct($dbconfig) {
-        $this->dbconfig = $dbconfig;
-        
-        $this->parseDatabaseConfig();
-    }
-
-    /**
-     * Parses the contents of the database configuration file so that individual settings can be retrieved.
-     *
-     */
-    public function parseDatabaseConfig() {
-        $this->databaseConfig = parse_ini_file($this->dbconfig);
-    }
-
-    /**
-     * Returns the value of the named item from the database configuration file
-     *
-     * @param string $key Name of the setting to retrieve
-     */
-    public function getDatabase($key) {
-        if (!isset($this->databaseConfig[$key])) {
-            throw new Sihnon_Exception_DatabaseConfigMissing($key);
-        }
-
-        return $this->databaseConfig[$key];
-    }
-
-    /**
-     * Sets the database instance used by this object
-     * 
-     * @param Sihnon_Database $database Database instance
-     */
-    public function setDatabase(Sihnon_Database $database) {
-        $this->database = $database;
-        $this->preload();
-    }
-
-    /**
-     * Loads the entire list of settings from the database
-     * 
-     */
-    private function preload() {
-        if (!$this->database) {
-            throw new Sihnon_Exception_NoDatabaseConnection();
-        }
-
-        $this->settings = $this->database->selectAssoc('SELECT name,type,value FROM settings', 'name', array('name', 'value', 'type'));
+    public function __construct($backend, $options) {
+        $this->backend = Sihnon_Config_PluginFactory::create($backend, $options);
+        $this->settings = $this->backend->preload();
     }
 
     /**