Add minimum quotas for users to earn the ability to create custom forums.
The entry requirements that could earn the first forum include:
1. Having a Certified account status for at least 45 days.
2. Having written 10 posts or replies in the forums.
Additional quota is granted in increasing difficulty based on the count of
forum posts created.
Other changes:
* Admin view of Manage Forums can filter for official/community.
* "Certified Since" now shown on profile pages.
* Update FAQ page for Forums feature.