More flexible distributions

[KScl]

Distributions can contain more than a fixed percentage of vanilla and mods. They can also now contain:

• Score-based pools (all modules that fit the specified score criteria, aren't needies, and don't have dynamic scoring get placed into the pool)
• Fixed pools (Name specific modules, and they'll be present)
• All Solvable pools are of course still available.
• Pools with a ≤0 weight are now treated as fixed spawns, allowing for things like a force spawn distribution or a +needy distribution.

As an example:

    "test": {
      "DisplayName": "Testing Mix",
      "Pools": [
        {
          "Definition": "ALL_SOLVABLE, MODS",
          "Weight": 0.5
        },
        {
          "Definition": "SCORE, <= 7",
          "Weight": 0.5,
          "Reward": 3,
          "Time": 120
        },
        {
          "Definition": "FIXED, spwizTetris",
          "Weight": 0.0,
          "Reward": 70,
          "Time": 0
        }
      ],
      "MinModules": 2,
      "MaxModules": 101,
      "Enabled": true,
      "Hidden": false
    },

As a result of this change, a couple additional changes happened:

• It is now required to return to the setup room instead of retrying if any profiles have been added or removed, or the game mode has been changed. As a result of this new requirement, profile changes can now be done during gameplay again, as the previous vectors for a softlock are no longer possible.
• "!run zen" was removed, based on the fact that it was never used anyway.
• Pacing events for !run bombs can now be disabled as a setting.

This closes #474.