I've decided to completely rewrite a PHP framework (Using MVC) that I've been working on, on and off, for years. My problem up until now was that I would just come up with ideas, throw them into Trac as tickets, and add them later - without worrying about the design of the framework itself. Over time this has caused some problems and I think a rewrite would be helpful, however I'm not sure where to begin with the planning of it - I know I don't want to use Trac, and I know I need more than just tickets and milestones - but what else would I need?
I really want to thoroughly plan this rewrite out, I want to detail every feature I want, where it will go, and how it will connect to every other part - but I have no experience with this level of planning. Any advice? Any programs that will help? I'm getting tired of Trac, I've never really liked it.
I know I'll need a design document, but is there any certain layout I should follow? I'll also need bug tracking, tickets, milestones, etc., but beyond Trac I don't know what's good for that either. I'm sure there's more I'll need but I have no idea what, so any help would be appreciated.