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/lib/logging.sh

@@ -0,0 +1,137 @@
+#!/bin/bash
+
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Handler for when we exit automatically on an error.
+# Borrowed from https://gist.github.com/ahendrix/7030300
+kube::log::errexit() {
+  local err="${PIPESTATUS[@]}"
+
+  # If the shell we are in doesn't have errexit set (common in subshells) then
+  # don't dump stacks.
+  set +o | grep -qe "-o errexit" || return
+
+  set +o xtrace
+  local code="${1:-1}"
+  kube::log::error_exit "'${BASH_COMMAND}' exited with status $err" "${1:-1}" 1
+}
+
+kube::log::install_errexit() {
+  # trap ERR to provide an error handler whenever a command exits nonzero  this
+  # is a more verbose version of set -o errexit
+  trap 'kube::log::errexit' ERR
+
+  # setting errtrace allows our ERR trap handler to be propagated to functions,
+  # expansions and subshells
+  set -o errtrace
+}
+
+# Print out the stack trace
+#
+# Args:
+#   $1 The number of stack frames to skip when printing.
+kube::log::stack() {
+  local stack_skip=${1:-0}
+  stack_skip=$((stack_skip + 1))
+  if [[ ${#FUNCNAME[@]} -gt $stack_skip ]]; then
+    echo "Call stack:" >&2
+    local i
+    for ((i=1 ; i <= ${#FUNCNAME[@]} - $stack_skip ; i++))
+    do
+      local frame_no=$((i - 1 + stack_skip))
+      local source_file=${BASH_SOURCE[$frame_no]}
+      local source_lineno=${BASH_LINENO[$((frame_no - 1))]}
+      local funcname=${FUNCNAME[$frame_no]}
+      echo "  $i: ${source_file}:${source_lineno} ${funcname}(...)" >&2
+    done
+  fi
+}
+
+# Log an error and exit.
+# Args:
+#   $1 Message to log with the error
+#   $2 The error code to return
+#   $3 The number of stack frames to skip when printing.
+kube::log::error_exit() {
+  local message="${1:-}"
+  local code="${2:-1}"
+  local stack_skip="${3:-0}"
+  stack_skip=$((stack_skip + 1))
+
+  local source_file=${BASH_SOURCE[$stack_skip]}
+  local source_line=${BASH_LINENO[$((stack_skip - 1))]}
+  echo "!!! Error in ${source_file}:${source_line}" >&2
+  [[ -z ${1-} ]] || {
+    echo "  ${1}" >&2
+  }
+
+  kube::log::stack $stack_skip
+
+  echo "Exiting with status ${code}" >&2
+  exit "${code}"
+}
+
+# Log an error but keep going.  Don't dump the stack or exit.
+kube::log::error() {
+  echo "!!! ${1-}" >&2
+  shift
+  for message; do
+    echo "    $message" >&2
+  done
+}
+
+# Print an usage message to stderr.  The arguments are printed directly.
+kube::log::usage() {
+  echo >&2
+  local message
+  for message; do
+    echo "$message" >&2
+  done
+  echo >&2
+}
+
+kube::log::usage_from_stdin() {
+  local messages=()
+  while read -r line; do
+    messages+=$line
+  done
+
+  kube::log::usage "${messages[@]}"
+}
+
+# Print out some info that isn't a top level status line
+kube::log::info() {
+  for message; do
+    echo "$message"
+  done
+}
+
+kube::log::info_from_stdin() {
+  local messages=()
+  while read -r line; do
+    messages+=$line
+  done
+
+  kube::log::info "${messages[@]}"
+}
+
+# Print a status line.  Formatted to show up in a stream of output.
+kube::log::status() {
+  echo "+++ $1"
+  shift
+  for message; do
+    echo "    $message"
+  done
+}