Fix bug when editing a page, the theme wasn't including blank

app/models/design/layout.rb

@@ -12,7 +12,7 @@ class Layout < DesignFile
   after_save :parse_layout
 
   def content
-    self.file.read.force_encoding("UTF-8")
+    self.file.read.force_encoding("UTF-8") rescue ''
   end
 
   def self.exist_one?

app/models/purchase/purchase.rb

@@ -6,6 +6,6 @@ class Purchase
   field :title
   field :author
   field :intro
-  field :downloaded
+  field :downloaded, :type => Boolean
 
 end

app/views/admin/pages/_form.html.erb

@@ -25,7 +25,7 @@
 <p>
 	<%= t('admin.theme') %>
 	<% if @design %>
-		<%= f.select :theme_id, @design.themes.collect { |t| [t.name.capitalize, t.id] }%>
+		<%= f.select :theme_id, @design.themes.collect { |t| [t.name.capitalize, t.id] }, :include_blank => true %>
 	<% else %>
 		<%= f.select :theme_id, @default_design.themes.collect { |t| [t.name.capitalize, t.id] }, :include_blank => true %>
 	<% end %>