[feature/avatars] Support proper avatar deletion, stub ACP

Fixing avatar deletion in the UCP and ACP, and stubbing the ACP
configuration page. I'll admit I kind of got caught carried away, so
this really should be a couple separate commits.

PHPBB3-10018

phpBB/includes/avatar/driver.php

@@ -114,4 +114,12 @@ abstract class phpbb_avatar_driver
 	{
 		return false;
 	}
+
+	/**
+	* @TODO
+	**/
+	public function delete($user_row)
+	{
+		return true;
+	}
 }

phpBB/includes/avatar/driver/upload.php

@@ -121,6 +121,22 @@ class phpbb_avatar_driver_upload extends phpbb_avatar_driver
 		);
 	}
 
+	/**
+	* @inheritdoc
+	*/
+	public function delete($user_row)
+	{
+		$ext = substr(strrchr($user_row['user_avatar'], '.'), 1);
+		$filename = $this->phpbb_root_path . $this->config['avatar_path'] . '/' . $this->config['avatar_salt'] . '_' . $user_row['user_id'] . '.' . $ext;
+
+		if (file_exists($filename))
+		{
+			@unlink($filename);
+		}
+
+		return true;
+	}
+
 	/**
 	* @TODO
 	*/

phpBB/includes/avatar/manager.php

@@ -47,6 +47,20 @@ class phpbb_avatar_manager
 			$this->load_valid_drivers();
 		}
 
+		// Legacy stuff...
+		switch ($avatar_type)
+		{
+			case AVATAR_LOCAL:
+				$avatar_type = 'local';
+				break;
+			case AVATAR_UPLOAD:
+				$avatar_type = 'upload';
+				break;
+			case AVATAR_REMOTE:
+				$avatar_type = 'remote';
+				break;
+		}
+
 		if (isset(self::$valid_drivers[$avatar_type]))
 		{
 			if ($new || !is_object(self::$valid_drivers[$avatar_type]))