fix growth bug

ruby script to fix the growth/size bug
script to inject steam engines

prevent typos and extra typing when trying to inject steam engines into
a current game
modified fix dead-units script

exports the cleared dead units to a file in the save directory so that
they can be restored later (so long as the fortress remains current)
janitor general ref fix

fixed adding general_ref_unit_workerst to job general_refs.  needed to
use df::allocate<> due to virtual functions
Growth Fix as a plugin

converted fix for the growth bug to a plugin