HTTP-TCP checks| Use the service_check interface
HTTP-TCP checks| Allow to configure event skipping

So that when server side service check are up, there is a solution
to avoid getting duplicate information
HTTP-TCP checks| Add tests for service checks
HTTP-TCP checks| Normalize the service checks name
HTTP-TCP checks| Make obvious in conf the default of not skipping events
Reflect the default argument in conf example
Merge pull request #986 from DataDog/rudy/http-tcp-service

Adding service_check to the HTTP and TCP checks