Add Subscribers navigation for single-user instances

Ref T826

templates/collection.tmpl

@@ -54,6 +54,7 @@
 							{{if .SimpleNav}}<li><a href="/new#{{.Alias}}">New Post</a></li>{{end}}
 							<li><a href="/me/c/{{.Alias}}">Customize</a></li>
 							<li><a href="/me/c/{{.Alias}}/stats">Stats</a></li>
+							<li><a href="/me/c/{{.Alias}}/subscribers">Subscribers</a></li>
 							<li class="separator"><hr /></li>
 							{{if not .SingleUser}}<li><a href="/me/c/"><img class="ic-18dp" src="/img/ic_blogs_dark@2x.png" /> View Blogs</a></li>{{end}}
 							<li><a href="/me/posts/"><img class="ic-18dp" src="/img/ic_list_dark@2x.png" /> View Drafts</a></li>

templates/user/include/header.tmpl

@@ -18,6 +18,7 @@
 				<nav class="tabs">
 					<a href="/me/c/{{.Username}}" {{if and (hasPrefix .Path "/me/c/") (hasSuffix .Path .Username)}}class="selected"{{end}}>Customize</a>
 					<a href="/me/c/{{.Username}}/stats" {{if hasSuffix .Path "/stats"}}class="selected"{{end}}>Stats</a>
+					<a href="/me/c/{{.Username}}/subscribers" {{if hasSuffix .Path "/subscribers"}}class="selected"{{end}}>Subscribers</a>
 					<a href="/me/posts/"{{if eq .Path "/me/posts/"}} class="selected"{{end}}>Drafts</a>
 				</nav>
 			</nav>