Versioning projects by stage

[loleg]

When Projects go through stages, the entire content (row) of the project should be made into snapshot. Users should also be able to save a snapshot at any point. They should be able to go back and see a history of the project data, and restore it. This basic wiki functionality would enhance the usability and stability of the platform, plus allow new insights into how the teams progress.

Originally posted as #91 (comment)