Add "refresh_frequency" option

Plugin.php

@@ -37,6 +37,26 @@ use Mibew\Plugin\PluginInterface;
  */
 class Plugin extends AbstractPlugin implements PluginInterface
 {
+    /**
+     * List of the plugin configs.
+     *
+     * @var array
+     */
+    protected $config;
+
+    /**
+     * Class constructor.
+     *
+     * @param array $config List of the plugin config. The following options are
+     * supported:
+     *   - 'refresh_frequency': int, time in seconds between button refreshes.
+     *     The default value is 3.
+     */
+    public function __construct($config)
+    {
+        $this->config = $config + array('refresh_frequency' => 3);
+    }
+
     /**
      * The plugin does not need extra initialization thus it is always ready to
      * work.
@@ -79,7 +99,7 @@ class Plugin extends AbstractPlugin implements PluginInterface
         if ($args['generator'] instanceof ImageGenerator) {
             // Only image buttons should be refreshed
             $script = HTML5\html('script');
-            $script->addChild($this->buildRefreshJs(3));
+            $script->addChild($this->buildRefreshJs($this->config['refresh_frequency']));
             $script->setAttribute('type', 'text/javascript');
 
             $last_index = count($args['button']->getChildren()) - 1;

README.md

@@ -14,9 +14,24 @@ If the "plugins" stucture looks like `plugins: []` it will become:
 plugins:
     -
         name: "Mibew:ButtonRefresh"
+        config: # Plugin's configurations are described below
+            refresh_frequency: 3
 ```
 
 
+## Plugin's configurations
+
+The plugin can be configured with values in "`<Mibew root>`/configs/config.yml" file.
+
+### config.ignore_emoticons
+
+Type: `Integer`
+
+Default: `3`
+
+Specify time in seconds between button refreshes. This value is optional and can be skipped.
+
+
 ## Build from sources
 
 There are several actions one should do before use the latest version of the plugin from the repository: