Restructuring the quests saved in TMW_Quest: write conversion function.

This function moves the content of TMW_Quest into nibbles of other variables.
o11c's review of the conversion function
Restructuring the quests saved in TMW_Quest: Convert Bernard and Mikhail to new variables.

The variable was also used in Kylian, so that script needed changes too.
o11c's review of bernard and mikhail
Restructuring the quests saved in TMW_Quest: Convert Sarah to new variables.
Restructuring the quests saved in TMW_Quest: Convert Vincent to new variables.
Restructuring the quests saved in TMW_Quest: Convert Sandra to new variables.
o11c's review of sandra
Restructuring the quests saved in TMW_Quest: Convert NPCs on 002-1 to new variables.
o11c's review of lt. dausen etc.
Restructuring the quests saved in TMW_Quest: Convert NPCs on 002-3 to new variables.
o11c's review of the outer mine
Restructuring the quests saved in TMW_Quest: Convert NPCs on 002-4 to new variables.
o11c's review of the inner mine
Restructuring the quests saved in TMW_Quest: Convert gossip to new variables.
Restructuring the quests saved in TMW_Quest: Convert Bandit quest NPCs to new variables.
Variable restructuring: move Quest_Scythe_state into Nibble 1 of QUEST_Hurnscald.
Variable restructuring: move Quest_demon_mines into Nibble 2 of QUEST_Hurnscald.
Demon Mask quest: don't open NPC dialog at barrier to the chest room.

Use message instead of mes, so the text is only displayed over the character's head.
Since the room has aggressive monsters in it, a NPC dialog box can be deadly.
Variable restructuring: move information about opening the chest in Hurnscald mines into FLAGS variable.