module results cache

• results of modules with specified project tags enabled can be cached
  • there are two module options that control this, "cache" and "cachefound"
    • "cache" can have a value of "public" or "private"
      • "cache":"public" is available to all users
      • "cache":"private" is only available to the logged on user
    • the optional "cachefound" tag can have values of "notify" or "askrecompute"
      • by default (no "cachefound" tag), the cache results are retrieved silently
      • "cache":"notify" will notify the user after job submission that cached results are being shown
      • "cache":"askrecompute" will present the user with the choice of showing previously computed results or recomputing them.
        • we could make this user specific to allow certain users only to recompute, please ask us if you need this.