Fixed relations being wiped out when saving

The code worked like this:

1. Delete old relations
2. Get related entities
3. Save old relations

If the entity hasn't retrieved relations until now, autoloader tried to
get related entities /after/ they were deleted.

src/Dao/PostDao.php

@@ -257,9 +257,6 @@ class PostDao extends AbstractDao implements ICrudDao
 
 	private function syncPostRelations(Post $post)
 	{
-		$this->pdo->deleteFrom('postRelations')->where('post1id', $post->getId())->execute();
-		$this->pdo->deleteFrom('postRelations')->where('post2id', $post->getId())->execute();
-
 		$relatedPostIds = array_filter(array_unique(array_map(
 			function ($post)
 			{
@@ -269,6 +266,8 @@ class PostDao extends AbstractDao implements ICrudDao
 			},
 			$post->getRelatedPosts())));
 
+		$this->pdo->deleteFrom('postRelations')->where('post1id', $post->getId())->execute();
+		$this->pdo->deleteFrom('postRelations')->where('post2id', $post->getId())->execute();
 		foreach ($relatedPostIds as $postId)
 		{
 			$this->pdo

src/Dao/TagDao.php

@@ -188,11 +188,6 @@ class TagDao extends AbstractDao implements ICrudDao
 
 	private function syncRelatedTagsByType(Tag $tag, array $relatedTags, $type)
 	{
-		$this->pdo->deleteFrom('tagRelations')
-			->where('tag1id', $tag->getId())
-			->where('type', $type)
-			->execute();
-
 		$relatedTagIds = array_filter(array_unique(array_map(
 			function ($tag)
 			{
@@ -202,6 +197,11 @@ class TagDao extends AbstractDao implements ICrudDao
 			},
 			$relatedTags)));
 
+		$this->pdo->deleteFrom('tagRelations')
+			->where('tag1id', $tag->getId())
+			->where('type', $type)
+			->execute();
+
 		foreach ($relatedTagIds as $tagId)
 		{
 			$this->pdo