Swagger: Supply per-route description and summary for each action

[lennartS-7cs]

Currently the Swagger description and summary of each action is used for all routes, e.g. given an Action named Foo with two routes (one GET and on POST for the usual collection interface) both routes will have the exact same description and summary (Foo->getDescription() and Foo->getSummary()) shown in Swagger.

While there may be some Actions where this makes a lot of sense, at least in the case of generic collections it does not.

My proposal would be to return maps from both these functions:

virtual const char* getDescription() const;
virtual const char* getSummary() const;

would then become

virtual const std::map<qttp::HttpPath, const char*> getDescription() const;
virtual const std::map<qttp::HttpPath, const char*> getSummary() const;

Swagger::initialize() would have to be changed accordingly.

I think this would not be such a big change, but really help with usability of the generated Swagger documentation. I'd be willing to implement this, if you don't see any roadblocks and would accept a pull request.

[lennartS-7cs]

If this issue would go forward it would also make sense to incorporate it for #27.

[lennartS-7cs]

I also updated the initial proposal with a cleaner API by using a std::map.

[lennartS-7cs]

I created a commit is a separate branch that implements this. Please note that it is not yet ready for a pull-request. I think a bit more discussion about the API and the consequences are necessary before that.

Once that has happened, I'm happy to take a look at the tests and examples as these are currently not adapted to the new API in the mentioned branch.