Added "Remember Playback Speed" option

Option to control the use of the last video's playback speed for a newly
loaded video

options.html

@@ -32,9 +32,13 @@
                 <input id="rewindTime" type="text" value=""/> 
             </div>
             <div class="row">
-                <label for="speedStep">Speed change step</label>
+                <label for="speedStep">Speed Change Step</label>
                 <input id="speedStep" type="text" value=""/>
             </div>
+            <div class="row">
+                <label for="rememberSpeed">Remember Playback Speed</label>
+                <input id="rememberSpeed" type="checkbox"/>
+            </div>
         </section>
 		
         <button id="save">Save</button>  <button id="restore">Restore Defaults</button>