Return invalid when repo not found for mapping

Return invalid error when attempting to create an ImageRepositoryMapping
and the specified ImageRepository can't be found.
Merge pull request #75 from ncdc/mapping-404-when-repo-not-found

Merged by openshift-bot
Initial support for Config{} creation
Fixup readme and contributing for vagrant
Fixes for builds

Correct host docker socket logic (it was doing docker-in-docker if
USE_HOST_DOCKER_SOCKET was set, and vice versa) and add unit test for it.

Add SourceRef to BuildInput and correct the STI build strategy to use
SourceURI and SourceRef appropriately.
Merge pull request #53 from mfojtik/config

Merged by openshift-bot
Merge pull request #66 from derekwaynecarr/fixup_readme

Merged by openshift-bot
Merge pull request #76 from ncdc/build-fixes

Merged by openshift-bot
Add extra godoc doc.go files
Merge pull request #78 from smarterclayton/add_extra_godoc

Add extra godoc doc.go files
Fix problem with replicationController ops in kube command