Expose `planHelper.lua`

[SirLich]

All of the availablePlansFor<x>Objects should be exposed. Additionally, please expose the local data where you define per-asset things.

For example:

local huntPlanInfosByObjectType = {
    [gameObject.types.chicken.index] = basicHuntingInfo,
    [gameObject.types.alpaca.index] = spearHuntingInfo,
    [gameObject.types.mammoth.index] = spearHuntingInfo
}

This needs to be exposed so I can add my custom mob here.

[mjdave]

fixed in b20