FEATURE: remove dependency of Redcarpet

PERF: cache fancy_title in topics table

New pure ruby implementation is far more flexible and easier to amend.

spec/components/html_prettify_spec.rb

@@ -0,0 +1,30 @@
+require 'spec_helper'
+require 'html_prettify'
+
+describe HtmlPrettify do
+
+  def t(source, expected)
+    expect(HtmlPrettify.render(source)).to eq(expected)
+  end
+
+  it 'correctly prettifies html' do
+    t "<p>All's well!</p>", "<p>All&rsquo;s well!</p>"
+    t "<p>Eatin' Lunch'.</p>", "<p>Eatin&rsquo; Lunch&rsquo;.</p>"
+    t "<p>a 1/4. is a fraction but not 1/4/2000</p>", "<p>a &frac14;. is a fraction but not 1/4/2000</p>"
+    t "<p>Well that'll be the day</p>", "<p>Well that&rsquo;ll be the day</p>"
+    t %(<p>"Quoted text"</p>), %(<p>&ldquo;Quoted text&rdquo;</p>)
+    t "<p>I've been meaning to tell you ..</p>", "<p>I&rsquo;ve been meaning to tell you ..</p>"
+    t "<p>single `backticks` in HTML should be preserved</p>", "<p>single `backticks` in HTML should be preserved</p>"
+    t "<p>double hyphen -- ndash --- mdash</p>", "<p>double hyphen &ndash; ndash &mdash; mdash</p>"
+    t "a long time ago...", "a long time ago&hellip;"
+    t "is 'this a mistake'?", "is &lsquo;this a mistake&rsquo;?"
+    t ERB::Util.html_escape("'that went well'"), "&lsquo;that went well&rsquo;"
+    t '"that went well"', "&ldquo;that went well&rdquo;"
+    t ERB::Util.html_escape('"that went well"'), "&ldquo;that went well&rdquo;"
+
+    t 'src="test.png"&gt; yay', "src=&ldquo;test.png&rdquo;&gt; yay"
+
+    t ERB::Util.html_escape('<img src="test.png"> yay'), "&lt;img src=&ldquo;test.png&rdquo;&gt; yay"
+  end
+
+end