title: Select project category change event JIRA 6.3.15
body: <p>I'm using JIRA 6.3.15. I'm using <code>ProjectCategoryChangeEvent</code> to catch the event of changing project category. When this event is triggered I have to do something like that: A custom field "X" have a context for old project category "A" and a context for new project category "B" and if the X context for A is different of X context for B do something. The problem is that the event is triggered after the project category change is done and because of that the contexts will merge and always will be the same. </p>
  
  <p>Does someone know how can I trigger the event before the contexts are merged?</p>