add pdf and mobi libraries

inc/3rdparty/libraries/send2kindle/MOBIClass/ContentProvider.php

@@ -0,0 +1,22 @@
+<?php
+
+abstract class ContentProvider{
+	/**
+	 * Get the text data to be integrated in the MOBI file
+	 * @return string
+	 */
+	public abstract function getTextData();
+	/**
+	 * Get the images (an array containing the jpeg data). Array entry 0 will
+	 * correspond to image record 0.
+	 * @return array
+	 */
+	public abstract function getImages();
+	/**
+	 * Get the metadata in the form of a hashtable (for example, title or author).
+	 * @return array
+	 */
+	public abstract function getMetaData();
+}
+
+?>