Also use combined_movecost() for NPC moves, and path length calculation.
Move monster movecost calculation to its own function for consistency.
Use calc_movecost() for path length estimation.
Fix silly mistake.
Merge MK II power armor.
Merge pull request #1495 from yobbobanana/movecost_update

Oops.
Merge remote-tracking branch 'dda/master' into dda-master
Merge enhancements to mutation system.
Warning for (startx,width,starty,title,ents) constructor removed: tested ok. -1024 changed to UIMENU_INVALID in init();
Merge branch 'better_menu' into advanced_inv_better_popups
Comment typo fixes
Don't despawn monsters when exiting the game, they're already saved elsewhere.
Made high strength characters on meth not break the disease duration
Made gasoline pumps only break when used

Fixes issue #1427
Convert some more stuff to using choose_adjacent().
Changed M72 LAW description to be more accurate

Closes #1499
Closes #800
Bugfix for incorrect item spawn location in mansion bedrooms
Clean plans member of monster object when loading from file.
Prevents pathological corner-case where
save -> exit -> start -> load -> repeat, with no intervening
player actions causes geometric growth of <player name>.sav
and the resulting monster array size.
Streamline special mutagen type handling by routing them theough a single iuse function.
Description tweak.