Refactors Newsletters as per @badshark's comments

lib/Newsletter/Renderer/Blocks/Header.php

@@ -0,0 +1,32 @@
+<?php namespace MailPoet\Newsletter\Renderer\Blocks;
+
+use MailPoet\Newsletter\Renderer\StylesHelper;
+
+class Header {
+
+  static function render($element) {
+    $stylesHelper = new StylesHelper();
+
+    // apply link styles
+    if(isset($element['styles']['link'])) {
+      $element['text'] = str_replace('<a', '<a style="' . $stylesHelper->getStyles($element['styles'], 'link') . '"', $element['text']);
+    }
+    
+    // apply text styles
+    if(isset($element['styles']['link'])) {
+      $element['text'] = str_replace('<p', '<p style="' . $stylesHelper->getStyles($element['styles'], 'text') . '"', $element['text']);
+    }
+    
+    $template = '
+    <tr>
+      <td class="mailpoet_col mailpoet_header"
+          style="' . $stylesHelper->getBlockStyles($element) . '"
+          valign="top">
+        <div>' . $element['text'] . '</div>
+      </td>
+    </tr>';
+    
+    return $template;
+  }
+
+}