MultiHex Map Seeding

[BenSmithers]

Want to swap out the RNG in MultiHex in a way that allows for seeding.

Idea for solution:

• Make new class, the RNGService, that can be seeded. This object will be capable of
  • generating a float uniformly between (0,1)
  • generating an integer uniformly between (0,N) where N is an integer >0.
  • Being seeded
• The RNGService will be persistent and shared by the all children of the application. Things that use the service will be passed a pointer (or use parent-child relations) to the RNG service.
• All RNG calls will use the service.

Note: there's probably already something that does exactly this. Should check!