refactor /user/site-settings.html template (nav. menu updates).

The nav. menu section sends a hidden value if a check box isn't
selected. This is in preparation for implementing the back-end part of
this feature.

I, also, removed the if-statements when selecting the home page in the
'Home Page' settings. Again, this in preparation for adjusting the
back-end functionality for this feature.

templates/user/site-settings.html

@@ -15,20 +15,30 @@
     <input type="submit" value="Save Changes">
 </form>
 
+<h2>Nav. Menu</h2>
+<form action="/site-settings/update-nav-menu" method="post">
+    <input required type="hidden" name="AUTHENTICITY-TOKEN" value="{{token}}">
+    {% for page in pages %}
+    <input type="hidden" name="NAV-MENU[{{page.slug}}]" value="off">
+    <input type="checkbox" name="NAV-MENU[{{page.slug}}]"
+	   {% if page.enable-nav-menu == 1 %}
+	   value="on"
+	   checked
+	   {% endif %}
+    >
+    <label>{{page.title}}</label>
+    {% endfor %}
+    <input type="submit" value="Update Nav. Menu">
+</form>
+
 <h2>Home Page</h2>
 <form action="/site-settings/update-home-page" method="post">
     <input required type="hidden" name="AUTHENTICITY-TOKEN" value="{{token}}">
     <p>Currently set to: {{settings.home-page}}</p>
     <select required name="SET-HOME-PAGE">
 	<option>Select Page</option>
-	{% for page in system-data.last.first%}
-	{% if page.slug == "login" %}
-	{% elif page.slug == "archive" %}
-	{% elif page.slug == "sign-up" %}
-	{% elif page.slug == "pages" %}
-	{% else %}
+	{% for page in pages %}
 	<option value="{{page.slug}}">{{page.title}}</option>
-	{% endif %}
 	{% endfor %}
     </select>
     <input type="submit" value="Set Home Page">