Revert "Change in_array to isset key lookups. This should make the whole faster (Fix Pieter's TODO from 2011)"
Revert "Change in_array to isset key lookups. This should make the whole faster (Fix Pieter's TODO from 2011)"

This reverts commit 7181863c

iRail/iRail,iRail/iRail,iRail/iRail