Use Railties to get routes information instead of 'rake routes'

Hi, 
I found that using 'rake routes' and parsing each line does not work in all case.
For example, it will get error in this case:
```
$ rake routes
Connecting to database specified by database.yml
Starting the New Relic Agent.
NewRelic Agent Developer Mode enabled.
To view performance information, go to http://localhost:3000/newrelic
Installed New Relic Browser Monitoring middleware
                           root        /                                          home#index
```

So I decide to change the method `#get_controller_info` a bit, that uses Railties to get the correct routes information.
I also change `#generate_resource_templates` so that it can get the user's defined template from `/config/rapi_doc/`

Thanks.