Improve source code highlighting.

Thanks to tips from http://demisx.github.io/jekyll/2014/01/13/improve-code-highlighting-in-jekyll.html

Author: willkoehler

_assets/stylesheets/_article.scss

@@ -171,14 +171,6 @@ article {
     }
 
 
-    .highlight {
-        border:0;
-
-        .lineno {
-            color:$textmuted;
-        }
-    }
-
     pre {
         border: 0;
         padding: 1.5em 3em;

_assets/stylesheets/_syntax.scss

@@ -57,4 +57,19 @@
 .highlight .vc { color: #008080 } /* Name.Variable.Class */
 .highlight .vg { color: #008080 } /* Name.Variable.Global */
 .highlight .vi { color: #008080 } /* Name.Variable.Instance */
-.highlight .il { color: #009999 } /* Literal.Number.Integer.Long */
+.highlight .il { color: #009999 } /* Literal.Number.Integer.Long */
+
+// suggestions from http://demisx.github.io/jekyll/2014/01/13/improve-code-highlighting-in-jekyll.html
+.highlight .lineno {
+  color: #ccc;
+  display: inline-block;
+  padding: 0 5px;
+  border-right: 1px solid #ccc;
+}
+.highlight pre code {
+  font: 13px Menlo, Monaco, Consolas, "Courier New", monospace;
+  display: block;
+  white-space: pre;
+  overflow-x: auto;
+  word-wrap: normal;
+}