Simplify code block line numbers

This pretty much undoes ddf7c09. Check out that commit for motivation on
why it was that way.

app/helpers/application_helper.rb

@@ -31,15 +31,7 @@ def tip_of_the_day
     render 'common/tip_of_the_day', tip: Tip.current
   end
 
-  # A *very* ugly way to get CodeRay to display formatted code in the way we
-  # want it. Naturally, using the table format in CodeRay is good enough for
-  # just showing it, but commenting on specific lines add a bunch of
-  # requirements on what we want to show.
   def format_code(code)
-    content_tag :table, class: 'CodeRay' do
-      lines = CodeRay.scan(code, Language.language).html(line_numbers: :inline, bold_every: false, line_number_anchors: false, css: :class).lines
-      rows  = lines.map { |line| line.sub %r{\A<span class="line-numbers">(\s*\d+)</span>(.*)\Z}, '<tr><td>\1</td><td>\2</td></tr>' }
-      rows.join("\n").html_safe
-    end
+    CodeRay.scan(code, Language.language).html(line_numbers: :table, bold_every: false, line_number_anchors: false, css: :class).html_safe
   end
 end

vendor/assets/stylesheets/coderay.css

@@ -25,9 +25,7 @@ span.CodeRay { white-space: pre; border: 0px; padding: 2px }
 
 table.CodeRay { border-collapse: collapse; width: 100%; padding: 2px }
 table.CodeRay td { vertical-align: top; }
-table.CodeRay td:first-child { width: 30px; padding-right: 10px; text-align: right; }
-table.CodeRay tr:first-child td { padding-top: 1ex; }
-table.CodeRay tr:last-child td { padding-bottom: 1ex; }
+table.CodeRay td:first-child { width: 30px; text-align: right; }
 
 .CodeRay .line-numbers, .CodeRay .no {
   background-color: #ECECEC;