Rework hack/ and build/ directories.

* Rewrite a bunch of the hack/ directory with modular reusable bash libraries.
* Have 'build/*' build on 'hack/*'.  The stuff in build now just runs hack/* in a docker container.
* Use a docker data container to enable faster incremental builds.
* Standardize output to _output/{local,dockerized}/bin/OS/ARCH/*.  This regularized placement makes cross compilation work.
* Move travis specific scripts under hack/travis

With new dockerized incremental builds, I can do a no-op `make quick-release` in ~30s.  This is a significant improvement.

hack/test-integration.sh

@@ -19,34 +19,28 @@ set -o nounset
 set -o pipefail
 
 KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
-source "${KUBE_ROOT}/hack/config-go.sh"
-source "${KUBE_ROOT}/hack/util.sh"
+source "${KUBE_ROOT}/hack/lib/init.sh"
 
 cleanup() {
-  kill "${ETCD_PID-}" >/dev/null 2>&1 || :
-  rm -rf "${ETCD_DIR-}"
-  echo ""
-  echo "Complete"
+  kube::etcd::cleanup
+  kube::log::status "Integration test cleanup complete"
 }
 
-if [[ "${KUBE_NO_BUILD_INTEGRATION+set}" != "set" ]]; then
+if [[ -z ${KUBE_NO_BUILD_INTEGRATION-} ]]; then
     "${KUBE_ROOT}/hack/build-go.sh" cmd/integration
 fi
 
 # Run cleanup to stop etcd on interrupt or other kill signal.
 trap cleanup HUP INT QUIT TERM
 
-start_etcd
+kube::etcd::start
 
-echo ""
-echo "Integration test cases..."
-echo ""
-GOFLAGS="-tags 'integration no-docker' -test.v" \
+kube::log::status "Running integration test cases"
+KUBE_GOFLAGS="-tags 'integration no-docker' -test.v" \
   "${KUBE_ROOT}/hack/test-go.sh" test/integration
 
-echo ""
-echo "Integration scenario ..."
-echo ""
-"${KUBE_TARGET}/bin/integration"
+kube::log::status "Running integration test scenario"
+
+"${KUBE_OUTPUT_HOSTBIN}/integration"
 
 cleanup