Fix page titles

zoe_api/web/templates/base_user.html

 {% extends "base.html" %}
 
 {% block content %}
-    <h1>Zoe - Analytics on demand</h1>
     {{ super() }}
 {% endblock %}
 

zoe_api/web/templates/execution_inspect.html

 {% extends "base_user.html" %}
 {% block title %}Inspect execution {{ e.name }}{% endblock %}
 {% block content %}
+<h1>Zoe - Analytics on demand</h1>
 <h2>Detailed information for execution {{ e.name }}</h2>
 <div id="contents">
 <ul>

zoe_api/web/templates/execution_new.html

 {% extends "base_user.html" %}
 {% block title %}New execution definition{% endblock %}
 {% block content %}
+    <h1>Zoe - Analytics on demand</h1>
 
-<h1>New execution</h1>
+<h2>New execution</h2>
     <form method="post" action="{{ reverse_url('execution_start') }}" enctype="multipart/form-data">
     <label>Execution name: <input type="text" name="exec_name"></label><br>
     <label>Application description: <input type="file" name="file"></label><br>

zoe_api/web/templates/home_user.html

 {% extends "base_user.html" %}
 {% block title %}Home{% endblock %}
 {% block content %}
+    <h1>Zoe - Analytics on demand</h1>
 
     <div id="my_executions">
     <h3>Executions</h3>