Add IgnoreOriginRule-related entities, db migration, update config

Add IgnoreOriginUserRule for user-defined rules and
IgnoreOriginInstanceRule for system-wide rules. Add an interface for
these two new entities.

Signed-off-by: Kevin Decherf <kevin@kdecherf.com>

src/Wallabag/CoreBundle/Repository/IgnoreOriginInstanceRuleRepository.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Wallabag\CoreBundle\Repository;
+
+use Doctrine\ORM\EntityRepository;
+
+class IgnoreOriginInstanceRuleRepository extends EntityRepository
+{
+}

src/Wallabag/CoreBundle/Repository/IgnoreOriginUserRuleRepository.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Wallabag\CoreBundle\Repository;
+
+use Doctrine\ORM\EntityRepository;
+
+class IgnoreOriginUserRuleRepository extends EntityRepository
+{
+}