Catch exceptions from tag::add() that can be caused by character

encoding issues resulting from embedded keywords in encodings we can't
decipher.  This can lead to weird truncation issues which in turn can
lead to multiple tags getting truncated to the same value in MySQL
which leads to mysql complaining that we're adding a duplicate tag.

Signed-off-by:  <unostar@danalan.info>

modules/tag/helpers/tag_event.php

@@ -45,7 +45,12 @@ class tag_event_Core {
 
     // @todo figure out how to read the keywords from xmp
     foreach(array_keys($tags) as $tag) {
-      tag::add($photo, $tag);
+      try {
+        tag::add($photo, $tag);
+      } catch (Exception $e) {
+        Kohana::log("error", "Error adding tag: $tag\n" .
+                    $e->getMessage() . "\n" . $e->getTraceAsString());
+      }
     }
 
     return;