Allow SessionsController to be used without authenticatable.

TODO

@@ -1 +1,3 @@
 * Make test run with different ORMs
+* Add registerable support
+* Add http authentication support

app/views/sessions/new.html.erb

@@ -1,18 +1,20 @@
 <h2>Sign in</h2>
 
-<% form_for resource_name, resource, :url => session_path(resource_name) do |f| -%>
-  <p><%= f.label :email %></p>
-  <p><%= f.text_field :email %></p>
+<%- if devise_mapping.authenticatable? %>
+  <% form_for resource_name, resource, :url => session_path(resource_name) do |f| -%>
+    <p><%= f.label :email %></p>
+    <p><%= f.text_field :email %></p>
 
-  <p><%= f.label :password %></p>
-  <p><%= f.password_field :password %></p>
+    <p><%= f.label :password %></p>
+    <p><%= f.password_field :password %></p>
 
-  <% if devise_mapping.rememberable? -%>
-    <p><%= f.check_box :remember_me %> <%= f.label :remember_me %></p>
-  <% end -%>
+    <% if devise_mapping.rememberable? -%>
+      <p><%= f.check_box :remember_me %> <%= f.label :remember_me %></p>
+    <% end -%>
 
-  <p><%= f.submit "Sign in" %></p>
-<% end -%>
+    <p><%= f.submit "Sign in" %></p>
+  <% end -%>
+<% end%>
 
 <%- if devise_mapping.recoverable? %>
   <%= link_to "Forgot password?", new_password_path(resource_name) %><br />