Profile import/export

[CovertDuck]

Thinking over #34, I think it would be to create some way to import and export human-readable JSON. One could easily backup his profile that way, and someone importing a profile could lead to multiple use cases:

1. Reset current games, import JSON
2. Keep current games, import JSON
   2.1 No conflicts
   2.2 Overwrite conflicts
   3.3 Keeps user's game edits, and import all from the JSON that don't conflict/overwrite