"my issues" should include issues I've commented on

People have a hard time finding issues they've commented on, see http://drupal.org/node/13221. Also we have inconsistent behaviour in project module: when I subscribe to receive emails about my "own issues", those issues include ones I've commented on, but when I view "my issues" I only get ones I created or that were assigned to me.

We already have a method for displaying issues I've created, been assigned, or commented on: the 'participated' key. The attached patch simply changes the current use of the 'users' key (which is for projects I created or am assigned) to the 'participated' key for my issues. That way, I'll see all issues I participated in at project/issues/user.