While working on the changes summed up in Bug 920485, the opportunity of refactoring the code and adding unit tests became progressively more and more apparent. This applies both to the original codebase and to the newly implemented parts. In particular, many methods are quite long and not covered by tests, reducing readability and making the code less robust. As soon as the changes detailed in Bug 920485 will be merged in a new consolidated codebase, I will proceed with some sound refactoring (hopefully with Rail's help!)