add link to 4.0 announcement

Hey IPS Dev/Staff:

May I suggest you add a link to the bug tracker in the announcement here:

http://community.invisionpower.com/announcement/31-ips-community-suite-40/

All you have to do is add a link to the words "bug tracker."

It would be easier for people to find the bug tracker than having to hunt for it by checking the innocuous navigation tab that says 'IPS4 resources.'

Brian