Disable internal link processing for asciidoc

asciidoc's representation of section identifiers interferes with
Gollum's page linking. This disables Gollum's page link tag
extraction for asciidoc files.

test/test_markup.rb

@@ -588,6 +588,19 @@ np.array([[2,2],[1,3]],np.float)
     compare(content, output, 'md')
   end
 
+  #########################################################################
+  # Asciidoc
+  #########################################################################
+
+  test "asciidoc header" do 
+    compare("= Book Title\n\n== Heading", '<div class="sect1"><h2 id="wiki-_heading">Heading</h2><div class="sectionbody"></div></div>', 'asciidoc')
+  end
+
+  test "internal links with asciidoc" do 
+    compare("= Book Title\n\n[[anid]]\n== Heading", '<div class="sect1"><h2 id="wiki-anid">Heading</h2><div class="sectionbody"></div></div>', 'asciidoc')
+  end
+
+
   #########################################################################
   #
   # Helpers