- https support for consul

- subscriber deadlock fix
- selector top level option

Performance improvements

- http broker using a registry cache
- selector lazy loading the watcher
- selector cache withstand registry failure
- selector cache used by default
- connection pooling set to 1 by default

- sort handler/subscriber endpoints

- pass options to new subscriber

Bug fix nil consul http client

respond when codec errors out

Fix potential panic/waitgroup bug

Initial release