Make individual controller actions asynchronous.
Extend validation for ReplicationController

Provide type safe checks for empty sets of selectors.
Solve issue with realpath on Mac OS X.

* realpath doesn't work on Mac OS systems. I found the following
  workaround that should work in any distro. For more references see the
  following: http://serverfault.com/questions/40144/how-can-i-retrieve-the-absolute-filename-in-a-shell-script-on-mac-os-x
health: Improve test coverage
Update Service and ReplControllers to validate

Validations are performed on update and on create.
Remove cmd/integration from hack/build-go.sh

Covered by hack/integration-test.sh in travis
Stopy proxying etcd (localhost:4001) on https:/$MASTER_IP/etcd.
Travis should test that build-go.sh generated something

Add a new hack/test-cmd.sh that tries to use the generated
executables in a meaningful way.  It does not require Docker
so as to be runnable in Travis
Disable early error exit, since the salt script is broken for now.
See: https://github.com/saltstack/salt-bootstrap/pull/436
Merge pull request #667 from brendandburns/debian

Disable early error exit, since the salt script is broken for now.
Move CONTRIB{,UTING}.md so GitHub shows it

Leave an old anchor
Merge pull request #648 from kelseyhightower/improve_health_test_coverage

health: Improve test coverage
Merge pull request #668 from smarterclayton/move_contributing

Move CONTRIB{,UTING}.md so GitHub shows it
Merge pull request #666 from erictune/remove_etcd_proxying

Stopy proxying etcd (localhost:4001) on https:/$MASTER_IP/etcd.
Merge pull request #640 from rafael/fix-realpath-issue-on-mac

Solve issue with realpath on Mac OS X.
Merge pull request #623 from smarterclayton/validate_replication_controllers

Add validation to ReplicationControllers
Merge pull request #655 from smarterclayton/verify_travis_builds

Travis should test that build-go.sh generated something
Merge pull request #664 from smarterclayton/remove_integration_from_build-go

Remove cmd/integration from hack/build-go.sh
Add some more synchronization.
Exit if release.sh has errors.