Ensure proper matching for post ID's.

Fixes #145

-/php/tags.php

@@ -192,7 +192,7 @@ public static function is_relative_webcomic( $relative = 'first', $in_same_term
 			return false;
 		}
 
-		return ( $post->ID === $the_post->ID );
+		return ( ( int ) $post->ID === ( int ) $the_post->ID );
 	}
 
 	/** Is the query for a Webcomic-recognized attachment?