Heavy refactoring needed

[sbordeyne]

Before going any further down the development, the code will need some heavy refactoring, as pointed out by /u/Durinthal.

Eventually, two classes should be made : one for monsters, one for characters (the second one should be heavier).

/u/equationsofmotion also proposed a party manager that is written in python and available on github : https://github.com/Yurlungur/pyparty_manager This could be cool to add to the play interface ( and character class)

At last, the code will now be slit into different files, one for each generator, while keeping the functions.py file for other non related functions (read_config, log, dice_roll...)

Someone also suggested to use JSON for the config file. It definively could be a good idea, but to be more user friendly, maybe use YAML instead, I'm not sure.