DUNGEON_HGT considered harmful

[seebs]

With cavern_gen existing, it is potentially the case that the map as a whole has a height other than DUNGEON_HGT, and a width other than DUNGEON_WID. And not just "if level is zero, it could be TOWN_HGT".

Two options suggest themselves:

1. Modify cavern_gen to use DUNGEON_HGT and DUNGEON_WID for caverns, too, even if the actual cavern is then centered inside that.
2. Track down basically all uses of DUNGEON_HGT and fix them.

[nppangband]

For variants with small levels, like EYAngband and NPPAngband, the max dungeon height and width are stored in

p_ptr->cur_map_hgt
p_ptr->cur_map_wid

They are defined at dungeon generation.

[seebs]

At least so far, it appears that cave->height and cave->width are correct for the current level, the *_gen functions all seem to correctly (well, nearly correctly) set the dungeon dimensions appropriately.