Added some type checking functions, could be useful in reducing the number of errors thrown for material/flag parsing. May need to add a few more functions to make this entirely usable. "json_value_type get_value_type(std::string member)" would be a useful one. At the moment functionality is restricted to JsonObjects, I think I need to add type checking to JsonArrays as well
Added type check for single character string
Removed the JVT_CHAR and associated check. Turns out it seems pretty unnecessary.
Added JsonObject::get_object, and is_object check. So now it should be possible to do "member":{object data} for a single object instead of requiring an array "member":[{object data}] for single objects.
Merge json type checking
fix build warning