Variables for use in Mustache templates.

Added:

*   `docs?`:    True if `docs` contains text of any sort, False if
                it's empty.

*   `code?`:    True if `code` contains text of any sort, False if
                it's empty.

*   `empty?`:   True if both `code` and `docs` are empty.  False
                otherwise.

*   `header?`:  True if `docs` contains _only_ a HTML header.  False
                otherwise.

lib/rocco/layout.rb

@@ -18,9 +18,15 @@ class Rocco::Layout < Mustache
     num = 0
     @doc.sections.map do |docs,code|
       {
-        :docs  => docs,
-        :code  => code,
-        :num   => (num += 1)
+        :docs       =>  docs,
+        :docs?      =>  !docs.empty?,
+        :header?    =>  /^<h.>.+<\/h.>$/.match( docs ),
+
+        :code       =>  code,
+        :code?      =>  !code.empty?,
+
+        :empty?     =>  ( code.empty? && docs.empty? ),
+        :num        =>  (num += 1)
       }
     end
   end