I am quite familiar with and love using git, among other reasons due to its distributed nature. Now I'd like to set up some similarly distributed (FOSS) Project Management software with features similar to what Redmine offers, such as

• Issue & time tracking, milestones
• Gantt charts, calendar
• git integration, maybe some automatic linking of commits and issues
• Wiki (preferably with Mathjax support)
• Forum, news, notifications
• Multiple Projects

However, I am looking for a solution that does not require a permanently accesible server, i.e. like in git, each user should have their own copy which can be easily synchronized with others. However it should be possible to not have a copy of every Project on every machine. Since trac uses multiple instances for multiple projects anyway, I was considering using that, but I neither know how well it adapts to simply giting the database itself (which would be be easiest way to handle the distribution due to git being used anyway), nor does it include all of Redmine's feature.

So, can you recommend me a distributed project management software? If your suggestion is a software that usually runs on a server please include a description of the distribution method (e.g. whether simply putting the data in a git repository would do the trick), and if it's e.g. trac, please mention plugins required to include the features mentioned.