Misc edits: makefiles/ and jjb templates.

Makefile
config.mk
makefiles/consts.mk
makefiles/lint/jjb.mk
---------------------
  o config.mk - initial setup to support library and local makefiles.
  o Move jjb lint target (~test) into jjb.mk, conditional logging verbosity.

makefiles/git-submodules.mk
---------------------------
  o Restore skeleton git submodule dir(s) after 'make sterile' is used.
  o Some external repo content placed under revision control.
  o Odd state: make clean induces bogus git status 'deleted:'

jjb/api-test.yaml
-----------------
  o Lint cleanup, fixed a complaint about replacment of non-expansive !include token.

jjb/defaults.yaml
-----------------
  o jjb + LinuxFoundation submodules have gone stale.
  o note download sources for a pending upgrade.

jenkins_jobs.errors.JenkinsJobsException:
  Failed to find suitable template named '{project-name}-ci-jobs'
-----------------------------------------------------------------
  o Finding 2020 changeset(s) also fail linting with this problem.
  o Might have an intermittent failure to debug in here.
  o Several jobs have run cleanly in the interim.

Change-Id: I20a0f3f0f731d6f312e5798af6049afd2e18c1c9
diff --git a/makefiles/lint/jjb.mk b/makefiles/lint/jjb.mk
new file mode 100644
index 0000000..c85b8b9
--- /dev/null
+++ b/makefiles/lint/jjb.mk
@@ -0,0 +1,56 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 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.
+# -----------------------------------------------------------------------
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+
+##-------------------##
+##---]  TARGETS  [---##
+##-------------------##
+ifndef NO-LINT-JJB
+  lint : lint-jjb
+endif
+
+## -----------------------------------------------------------------------
+## Intent: Construct command line for linting jenkins-job-builder config
+## -----------------------------------------------------------------------
+
+ifdef DEBUG
+  lint-jjb-args += --log_level DEBUG#         # verbosity: high
+else
+  lint-jjb-args += --log_level INFO#          # verbosity: default
+endif
+lint-jjb-args += --ignore-cache
+lint-jjb-args += test#                        # command action
+lint-jjb-args += -o archives/job-configs#     # Generated jobs written here
+lint-jjb-args += --recursive
+lint-jjb-args += --config-xml#                # JJB v3.0 write to OUTPUT/jobname/config.xml
+lint-jjb-args += jjb/#                        # JJB config sources (input)
+
+lint-jjb:
+	jenkins-jobs $(lint-jjb-args)
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+help ::
+	@echo '  lint-jjb               Validate jjb job generation'
+ifdef VERBOSE
+	@echo '1    DEBUG=1                lint-jjb --log_level=DEBUG'
+endif
+
+# [EOF]