More entropy for foreign titles

* Treat strings with non-ASCII characters as having more entropy

lib/text_sentinel.rb

@@ -21,8 +21,10 @@ class TextSentinel
   end
 
   # Entropy is a number of how many unique characters the string needs.
+  # Non-ASCII characters are weighted heavier since they contain more "information"
   def entropy
-    @entropy ||= @text.to_s.strip.split('').uniq.size
+    chars = @text.to_s.strip.split('')
+    @entropy ||= chars.pack('M*'*chars.size).gsub("\n",'').split('=').uniq.size
   end
 
   def valid?

spec/components/text_sentinel_spec.rb

@@ -32,7 +32,15 @@ describe TextSentinel do
     end
 
     it "Works on foreign characters" do
-      TextSentinel.new("去年十社會警告").entropy.should == 7
+      TextSentinel.new("去年十社會警告").entropy.should == 19
+    end
+
+    it "generates enough entropy for short foreign strings" do
+      TextSentinel.new("又一个测").entropy.should == 11
+    end
+
+    it "handles repeated foreign characters" do
+      TextSentinel.new("又一个测试话题" * 3).entropy.should == 18
     end
 
   end