templates: expose above blocks for login and register pages.

rhodecode/templates/login.html

@@ -27,7 +27,7 b''
         <div class="left-column">
             <img class="sign-in-image" src="${h.url('/images/sign-in.png')}" alt="RhodeCode"/>
         </div>
-        
+        <%block name="above_login_button" />
         <div id="login" class="right-column">
             <%include file="/base/flash_msg.html"/>
             <!-- login -->

rhodecode/templates/register.html

@@ -27,7 +27,7 b''
         <div class="left-column">
             <img class="sign-in-image" src="${h.url('/images/sign-in.png')}" alt="RhodeCode"/>
         </div>
-        
+        <%block name="above_register_button" />
         <div id="register" class="right-column">
             <%include file="/base/flash_msg.html"/>
             <!-- login -->