Insert attachment v1.8 changes: Now works with XF 2.2 and newer.
Insert attachment v1.7 changes: Fixed issue where empty variable caused server error.
Insert attachment v1.6 changes: Now works with XF v2.0 and v2.1.
Insert attachment v1.5 changes: Fixed typo in variable.
Insert attachment v1.4 changes: Fixed issue dealing with inserting additional attachments if multiple attach codes are on the same line.
Insert attachment v1.2 changes: Updated thread.php file.
Insert attachment v1.1 changes: Updated addon.json file.