ioncache/Tag-Handler — pull request #16 by mphill22 (2012-03-04 15:52:05+00:00)
Title: Let onAdd/onDelete callbacks modify control flow

this small change allows the return code of the onAdd/onDelete callbacks stop an addition/deletion. False = stop action/true = continue.

Note for merging upstream, this could potentially break existing code if people have employed callbacks that unintentionally return false when upgrading to a newer version.