More page formatting

Added server-side logic for register.html validation
Keep form firelds on register.html in the event of wrong input fields to save users from retyping info
More button rounding

powerdnsadmin/templates/domain_setting.html

@@ -1,7 +1,13 @@
 {% extends "base.html" %}
-{% block title %}<title>Domain Management - {{ SITE_NAME }}</title>{% endblock %}
+
+{% block title %}
+  <title>
+    Domain Management - {{ SITE_NAME }}
+  </title>
+{% endblock %}
 
 {% block dashboard_stat %}
+
 {% if status %}
 {% if status.get('status') == 'ok' %}
 <div class="alert alert-success">
@@ -31,7 +37,7 @@
 {% block content %}
 <section class="content">
     <div class="row">
-        <div class="col-xs-12">
+        <div class="col-12">
             <div class="box">
                 <form method="post" action="{{ url_for('domain.setting', domain_name=domain.name) }}">
                     <input type="hidden" name="_csrf_token" value="{{ csrf_token() }}">