HTML validation + Actually associate messages to errors + Fix inverted behavior on new blog and post form

templates/blogs/new.html.tera

@@ -8,7 +8,7 @@
 {% block content %}
 <h1>{{ "Create a blog" | _ }}</h1>
 <form method="post">
-    {{ macros::input(name="title", label="Title", errors=errors, form=form) }}
+    {{ macros::input(name="title", label="Title", errors=errors, form=form, props='required minlength="1"') }}
 
     <input type="submit" value="{{ "Create blog" | _ }}"/>
 </form>