Display profession traits and more consistency checks

Displays the profession traits, as requested at https://github.com/CleverRaven/Cataclysm-DDA/pull/9723#issuecomment-61367342.

Added consistency checks for scenario traits, profession traits.

Extended the checks for tool quality: recognize duplicated entries (find the error: `"qualities": [["SAW_M",1],["SAW_M",3]]`), and use the json system for error reporting (which prints the surrounding json data and tells you the line number).

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- `traits` is a global variable - why? Can it be moved into the traits class, same with other things like `ma_styles`, `morale_data`?

- Would it be a good idea to make the whole new character build player object specific: remove reference to `g->u` and use `this` / a player reference as parameter instead. That allows to apply the whole process to npcs, building a npcs just like you build your own character.