Update Product version to 5.2

[concubidated]

This should be all the files that need to update. In game version looks right and it now create a Stepmania 5.2 folder for userdata.

[kyzentun]

Moving to a new userdata folder is going to force everyone to move their profiles and songs they have in userdata. Not a good idea.

[shakesoda]

I accept that this will require that people mv .stepmania-5.0 .stepmania-5.2 or a symlink. this is wildly overdue.