Merge pull request #363 from LostTemplar/duplicate

Duplicate cave and gear.
Fix monster remaining current after its turn bug (thanks Delvin)
Move monster energy calculations to process_monsters
Start using MFLAG_ACTV
Streamline monster direction choice, removing some biases (and some Moria code)
Start using monster targets (in a limited way so far)
Rename list-mon-flags.h to list-mon-race-flags.h
Add list-mon-temp-flags.h
Treat mflag as a bitflag
Move monster booleans to mflag
Remove mon-constants.h