One final patch before the weekend

Because we literally cannot help ourselves, more stuff:

· Bloomery provides warmth while not fully burning; blazing Bloomery is warmer;
· Exploration markers visibility status is now saved;
· Crop field cells now better indicate if they contain enough water;
· Players now leave a marker where they died;
· Character's remains now also indicate the cause of death when you interact with it, and also the name of the character that died there;
· Added exploration marker to Winter Invasion portal;
· Added map filter for character's remains;
· Added a proper complain message when the mine is exhausted;
· Fixed miners getting stuck in a fully exploited mine;
· Fixed some glitchy behavior when exiting ladders;
· Fixed regression with NPCs not properly adjusting their Y position accurately to match terrain height and swimming incorrectly

After hours = nobody here to make pretty update graphics. Luckily the code is beautiful enough.

Thanks everyone!
Sand Sailors