[ticket/12124] Revert to basic uploader if the html5 runtime is not supported.

PHPBB3-12124
[ticket/12124] Remove double bang.

PHPBB3-12124
[ticket/12124] Set attachment data to preserve AJAX delete functionality.

PHPBB3-12124
[ticket/12124] The textarea selector is failing in IE8 & 9.

PHPBB3-12124
[ticket/12124] IE8 does not support indexOf() for arrays.

PHPBB3-12124
Merge remote-tracking branch 'prototech/ticket/12124' into develop