Evaluate trac plugins to make sure they are secure to use

As part of an effort to better organize our work on Trac we need features that are not part of the core Trac. 

• verify if plug-ins are good to use:

  • multiple projects: https://trac-hacks.org/wiki/SimpleMultiProjectPlugin

  • dependencies, project planning, tracking states http://trac-hacks.org/wiki/ProjectPlanPlugin