Ruby 1.9 Compatibility

Completely removed the html5lib sanitizer.
Fixed the string-handling to work in both
Ruby 1.8.x and 1.9.2. There are still,
inexplicably, two functional tests that
fail. But the rest seems to work quite well.

attic/vendor/plugins/HTML5lib/lib/html5/sniffer.rb

@@ -0,0 +1,45 @@
+module HTML5
+module Sniffer
+  # 4.7.4
+  def html_or_feed str
+    s = str[0, 512] # steps 1, 2
+    pos = 0
+
+    while pos < s.length
+      case s[pos]
+      when ?\t, ?\ , ?\n, ?\r # 0x09, 0x20, 0x0A, 0x0D == tab, space, LF, CR
+        pos += 1
+      when ?< # 0x3C
+        pos += 1
+        if s[pos..pos+2] == "!--" # [0x21, 0x2D, 0x2D]
+          pos += 3
+          until s[pos..pos+2] == "-->" or pos >= s.length
+            pos += 1
+          end
+          pos += 3
+        elsif s[pos] == ?! # 0x21
+          pos += 1
+          until s[pos] == ?> or pos >= s.length # 0x3E
+            pos += 1 
+          end
+          pos += 1
+        elsif s[pos] == ?? # 0x3F
+          until s[pos..pos+1] == "?>" or pos >= s.length # [0x3F, 0x3E]
+            pos +=  1
+          end
+          pos += 2
+        elsif s[pos..pos+2] == "rss"   # [0x72, 0x73, 0x73]
+          return "application/rss+xml"
+        elsif s[pos..pos+3] == "feed"  # [0x66, 0x65, 0x65, 0x64]
+          return "application/atom+xml"
+        elsif s[pos..pos+6] == "rdf:RDF" # [0x72, 0x64, 0x66, 0x3A, 0x52, 0x44, 0x46]
+          raise NotImplementedError
+        end
+      else
+        break
+      end
+    end
+    "text/html"
+  end
+end
+end