Fix css bugs (opacity=) and changes in sign_in page

app/views/devise/sessions/new.html.erb

@@ -3,8 +3,8 @@
 	<h3><%= t(:login) %></h3>
 </div>
 <div id="container" class="sign-in">
-	  <% flash.each do |key, msg| %>
-    <%= content_tag :spen, msg, :class => [key, "notice label label-warning"] %>
+	<% flash.each do |key, msg| %>
+    <%= content_tag :span, msg, :class => [key, "notice label label-warning"] %>
   <% end%>
 	<%= form_for :user, :url => user_session_path, :html => {:class => 'user_new form-horizontal'} do |f| %>
 		<div class="content">