Regenerate the milestone when creating the package

[AlexJitianu]

The current flow is this:

1. Generate the milestone
2. Work on the files
3. Create the package for translation
4. Regenerate the milestone

Someone suggested to regenerate the milestone automatically when the package for translation is created, thus merging steps 3 and 4. I can see the benefit as someone might forget to manually regenerate the milestone. If that happens, the next package for translation will unnecessarily contain some files already translated.

The only benefit of having this separate step is if you misplace/delete the package. If we automatically regenerate the milestone, you wont be able to create the package again.

Let's have an option controlling this behavior. It remains to be seen what the default value will be.