Create generic configuration interface

[devin122]

Devise some sort of generic configuration interface for configuring runtime options on the various components.

Current sketch looks something like

class IConfigProvider {
public:
virtual string GetStringOption(const char* option_name) = 0;
int GetIntOption(cont char *option_name) = 0;
bool GetBoolOption(const char *option_name) = 0;
};

Open questions:

• How are string valued options returned, and who owns the memory
• Can modules provide some kind of schema to define what options they take, valid ranges, and/or default values?
• If components can provide schema, what does the flow look like in terms of providing that to the configuration provider? Presumably the components want to query configuration at construction time, thus the schema needs to be provided before construction