Initial commit: ZPL-native PDF printing, drop CUPS dependency

views/login_form.erb

@@ -0,0 +1,4 @@
+<form action='/login/attempt' method='post' class="form-inline well">
+  <input type="text" name='username' placeholder="username" autofocus>
+  <input class="btn primary" type='submit' value='log in'>
+</form>