Use entry title without whitespace as section id

docs/Rakefile

@@ -12,8 +12,12 @@ module ExtraFilters
     Maruku.new(input).to_html
   end
 
-  def sanitize(input)
-    input.gsub(/[^a-zA-Z0-9_]/,"")
+  def section_id(input)
+    input.gsub(/[^a-zA-Z0-9_]/, '')
+  end
+
+  def entry_id(input)
+    input.gsub(' ', '')
   end
 
   def no_paragraph(input)