Add ability to delete collections

app/templates/collections/delete.html

@@ -0,0 +1,17 @@
+{% extends "base.html" %}
+
+{% block title %}
+	{{ _('Delete collection "%(title)s" by %(author)s', title=collection.title, author=collection.author.username) }}
+{% endblock %}
+
+{% block content %}
+	<form method="POST" action="" class="card box_grey">
+		<input type="hidden" name="csrf_token" value="{{ csrf_token() }}" />
+		<h3 class="card-header">{{ self.title() }}</h3>
+		<div class="card-body">
+			<p>{{ _("Deleting is permanent") }}</p>
+			<a class="btn btn-secondary mr-3" href="{{ collection.get_url('collections.create_edit') }}">{{ _("Cancel") }}</a>
+			<input type="submit" value="{{ _('Delete') }}" class="btn btn-danger" />
+		</div>
+	</form>
+{% endblock %}

app/templates/collections/view.html

@@ -28,6 +28,9 @@
 			</form>
 		{% endif %}
 		{% if collection.check_perm(current_user, "EDIT_COLLECTION") %}
+			<a class="btn btn-danger ml-2" href="{{ collection.get_url('collections.delete') }}">
+				{{ _("Delete") }}
+			</a>
 			<a class="btn btn-primary ml-2" href="{{ collection.get_url('collections.create_edit') }}">
 				{{ _("Edit") }}
 			</a>