top-level makefile: install lua_scripts/init_modeconfig.lua
top-level makefile: install lua_scripts/init_modeconfig.lua

- this was left out from the previous commit, titled
  "Exec policy selection is now implemented in C"

OlegGirko/ldbox,h113331pp/scratchbox2,ldbox/ldbox,ldbox/ldbox,OlegGirko/ldbox,OlegGirko/ldbox,ldbox/ldbox,OlegGirko/ldbox,ldbox/ldbox,h113331pp/scratchbox2,h113331pp/scratchbox2,h113331pp/scratchbox2,h113331pp/scratchbox2,ldbox/ldbox,h113331pp/scratchbox2,OlegGirko/ldbox,OlegGirko/ldbox,ldbox/ldbox