Makefile library merge with onf-make and voltha-lib-go

makefiles/
----------
  o Import standalone makefile directories to checkin smaller parts of a mega patch.
  o Build out directory hierarchy by topic and feature.

makefiles/lint/yaml/
--------------------
  o Pull in logic evolved in repo:voltha-lib-go.
  o Refactoring: support special snowflake targets by repository.
  o ci-management and voltha-lib-go use distinct yamllint.conf files.
  o Separate until there is time to review and consolidate.
  o Added deps for on-demand local install of yamllint.
    - requirements.txt could be used but every build would incur overhead.

Makefile
--------
  o Use latest syntax from repo:onf-make.
  o No need to set path variables, makefiles/include.mk can infer them.
  o Added a help target to explicitly display targets and suggestions.
  o Logic is bundled in libraries and use of 'make help' is not well known.

Change-Id: Id8eba6f914a7bfe9a31637901bd8fb78a387e0c2
diff --git a/makefiles/bin/compare_sandbox_makefiles.sh b/makefiles/bin/compare_sandbox_makefiles.sh
new file mode 100755
index 0000000..28e47b0
--- /dev/null
+++ b/makefiles/bin/compare_sandbox_makefiles.sh
@@ -0,0 +1,66 @@
+#!/bin/bash
+# -----------------------------------------------------------------------
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# 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.
+#
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+# https://gerrit.opencord.org/plugins/gitiles/onf-make
+# ONF.makefile.version = 1.0
+# -----------------------------------------------------------------------
+# Intent: This script is used to bulk refactor and merge makefile changes
+##  between development repositories and repo:onf-make.
+## -----------------------------------------------------------------------
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+function error
+{
+    echo "$*"
+    exit 1
+}
+
+##----------------##
+##---]  MAIN  [---##
+##----------------##
+src="$HOME/projects/sandbox/onf-make/makefiles"
+# src="$HOME/projects/sandbox/ci-management/makefiles"
+dst="$(realpath .)"
+
+while [ $# -gt 0 ]; do
+    fyl=$1; shift
+
+    echo "FYL: $fyl"
+    if [ -d "$fyl" ]; then
+	readarray -t fyls < <(find "$fyl" -type f -print)
+	[[ ${#@} -gt 0 ]] && fyls+=("$@")
+	# declare -p fyls
+	[[ ${#fyls} -gt 0 ]] && set -- "${fyls[@]}"
+	continue
+    fi
+
+    src0="$src/$fyl"
+    dst0="$dst/$fyl"
+
+    [[ ! -e "$src0" ]] && error "File does not exist in src= $src0"
+    [[ ! -e "$dst0" ]] && error "File does not exist in dst= $dst0"
+
+    if ! diff -qr "$src0" "$dst0"; then
+	emacs "$src0" "$dst0"
+    fi
+done
+
+# [EOF]