Reverting the Sanitizer commit in case we have to do something urgent

before we deploy it early next week. It's in the branch `sanitizer` for
now.

This reverts commit 9e93d8ed5209c5c65dfa00fa9b9d17cc8de13244.

spec/components/pretty_text_spec.rb

@@ -32,7 +32,7 @@ describe PrettyText do
     end
 
     it "should sanitize the html" do
-      PrettyText.cook("<script>alert(42)</script>").should match_html "<p></p>"
+      PrettyText.cook("<script>alert(42)</script>").should match_html "alert(42)"
     end
 
     it 'should allow for @mentions to have punctuation' do