Addition of Functor to encapsulate static and non-static class member JsonObject loading functions
-- May need moving of Functor definitions to new file?
Fix for savegame compatability breakage relating to monster IDs.

Committing for AtomicDryad
Merge pull request #3347 from CIB/monster_savegame_fix

Merge fix for bugged legacy_mon_id.
Merge remote branch 'origin/pr/3164'

Conflicts:
	init.cpp: added lab_note and hint