Saving and loading game takes too long

[DavidFidge]

#41 fixed load game prompt speed. However actually performing a save game and load game is slow.

Most of the current problems are in the Monsters where it must serialize a large list of seen tiles. This means it will get worse as more levels are added to the game.

Writing a custom serializer for serializing map-related data such as map tile information, monster seen tiles etc should help:
https://www.newtonsoft.com/json/help/html/Performance.htm

Another thing to try would be to use BSON which would mean ints etc won't have to be converted to strings, though I doubt this is where the performance problems are:
https://www.newtonsoft.com/json/help/html/SerializeToBson.htm

[DavidFidge]

Tried BSON as it was a very quick change to do and test. The performance isn't much better. Plus it does not support unsigned 64 bit ints.

Will need to try custom serialisation.

[DavidFidge]

code for BSON is on branch 'saveload' in DavidFidge/FrigidRogue