#420 Make default slaying fields of locked doors and keys differ

[Saiapatsu]

This patch will give keys slaying set_individual_value_key and doors slaying set_individual_value_door.
It allows assuming that a door without a slaying field set has no key meant for it, and a key with no slaying field is not meant for any door.

The Tower of Demonology will be broken by this change because it uses default keys on MasterLevel and Demon1.
Patch 0002 will remove these doors and keys entirely.
Patch 0003 will instead give them proper keycodes.
The latter is preferable because it encourages the player to go up to talk to the cleaning woman.

[Nicolas Weeger]

Patches 0001 and 0003 applied as 0d2c4f5d31da5981e82fac6369f40d5240609a54 (arch) and b797012d36309efb2ffc7c5c84470f1208e78854 (maps).

Thanks!