RF: Remove layout randomness from the server.

All random events (such as the choosing of a layout) should be done in the pelitagame script and not in the backend.
RF: Having an idempotent ‘layout_string’ parameter seems a bit silly.
BF: Fix inconsistencies.
Merge pull request #223 from Debilski/feature/the-fight-against-classes-which-are-too-smart