on the homepage, don't show a toggle for left nav

Closes #745

Squashed commit of the following:

commit 1bb1c45
Author: Seth Ladd <[email protected]>
Date:   Wed Jul 29 15:43:03 2015 -0700

    on the homepage, don't show a toggle for left nav

Author: sethladd

lib/resources/styles.css

@@ -534,17 +534,6 @@ button {
   padding: 0;
 }
 
-#sidenav-right-toggle {
-  display: inline;
-  background: no-repeat url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24'><path fill='#FFFFFF' d='M3 18h18v-2H3v2zm0-5h18v-2H3v2zm0-7v2h18V6H3z'/></svg>");
-  background-position: center;
-  width: 24px;
-  height: 24px;
-  border: none;
-  display: none;
-  vertical-align: text-bottom;
-}
-
 /* left-nav disappears, and can transition in from the left */
 @media screen and (max-width:768px) {
   .main-content {

lib/templates/_head.html

@@ -27,7 +27,9 @@
 <header class="container-fluid" id="title">
     <nav class="navbar navbar-fixed-top">
         <div class="container">
+            {{^navLinks.isEmpty}}
             <button id="sidenav-left-toggle" type="button">&nbsp;</button>
+            {{/navLinks.isEmpty}}
             <ol class="breadcrumbs gt-separated hidden-xs">
                 {{#navLinks}}
                 <li><a href="{{href}}">{{name}}</a></li>
@@ -42,7 +44,9 @@
             {{#navLinks}}
             <li><a href="{{href}}">{{name}}</a></li>
             {{/navLinks}}
+            {{^navLinks.isEmpty}}
             <li class="self-crumb">{{self.name}}</li>
+            {{/navLinks.isEmpty}}
         </ol>
         <div class="title-description">
             <h1 class="title">