Make it possible for a town to re-roll their Resources for a fee.

[LlmDl]

Closes #122

Requires enabling it in the config and giving mayors the permission node to use the command:
/ta townyperms group towns.mayor addperm townyresources.command.town.reroll

  - New Config Option: town_resources.production.reroll_cost
    - Default: -1.0
    - When above 0, a town can pay to reroll their resources.
    - This is disabled by default to prevent rich towns being able to spam rerolls. Use cautiously.