Revert "Only load food.lua if hungermod is enabled."
Fixes #1047

This reverts commit 8197f529b412dfe22d7ae92962233dd272572057.
Reimplementation of the functionality that 8197f529 implemented.
@Bo98 Direct access tables in Lua are implemented by hash tables. The non-numeric keys of a table are hashed and stored in an array in the background. This makes looping order non-deterministic. Also, looping through a table with non-numeric keys should be slower than tables with numeric keys.

The problem happened because shipments loaded before jobs. Even though they are the second thing you add to the table, in the hash table in the background they were added before the jobs file.

Be more careful next time.