implements setCharset for mysql, no exception if setCharset is not implemented (fixes #244)

lib/Doctrine/Connection.php

@@ -450,13 +450,10 @@ abstract class Doctrine_Connection extends Doctrine_Configurable implements Coun
      * Set the charset on the current connection
      *
      * @param string    charset
-     * @param resource  connection handle
      *
-     * @throws Doctrine_Connection_Exception            if the feature is not supported by the driver
-     * @return true on success, MDB2 Error Object on failure
+     * @return void
      */
     public function setCharset($charset) {
-        throw new Doctrine_Connection_Exception('Altering charset not supported by this driver.');
     }
     /**
      * fetchAll

lib/Doctrine/Connection/Mysql.php

@@ -88,6 +88,17 @@ class Doctrine_Connection_Mysql extends Doctrine_Connection_Common {
 
         parent::__construct($manager, $adapter);
     }
+    /**
+     * Set the charset on the current connection
+     *
+     * @param string    charset
+     *
+     * @return void
+     */
+    public function setCharset($charset) {
+        $query = 'SET NAMES '.$this->dbh->quote($charset);
+        $this->dbh->query($query);
+    }
     /**
      * Returns the next free id of a sequence
      *