Merge pull request #362 from myshkin/restruct

Fix main-gcu's Term_xtra_gcu_react() to use new terrain constants.
Add some monster struct stuff
Replace mon_will_run with find_range
Known cave and gear alloc/free.
Save / load of duplicate cave and gear.
Used duplicate cave for features. It works more or less.
Fixed detect stairs / doors.
Commented out actual use of known features. It still remember them.
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
Fixed some irrelevant memory leaks.