Improve target coverage for the reuse license checker.

misc
----
  o Copyright notice update from onf v1 to onf v1.1

makefiles/etc/utils.mk
----------------------
  o Function path-by-makefilepath-by-makefile():
    - Replace $(subst include.mk) with $(dir) so path construction becomes generic.
    - Added wrapper function genpath-makefiles() to improve call usability.

makefiles/lint/license/include.mk
makefiles/lint/license/reuse.mk
makefiles/lint/license/install.mk
---------------------------------
  o Added requirements.txt for reuse tool install (ability to vesion and freeze for release).
  o Define command var REUSE= so local devs can override.
  o Added banner-{enter,leave} for logfile visibility.

makefiles/lint/license/include.mk

makefiles/lint/license/help.mk
------------------------------
  o Document a few missing targets for 'make help' and 'make lint-reuse-help'.

[HOWTO: test]
-------------
% make sterile
% make venv                 # install virtualenv
% make lint-reuse-install

% make sterile
% make lint-reuse-version

% make sterile
% make lint-reuse

Change-Id: I91f4789981f3d3c5bc744d2db99374f9790e3b98
diff --git a/makefiles/utils/include.mk b/makefiles/utils/include.mk
index 6090a17..e3e9ae0 100644
--- a/makefiles/utils/include.mk
+++ b/makefiles/utils/include.mk
@@ -39,15 +39,39 @@
 ##   groovy-check-conf := $(call path-by-makefile,.groovylintrc.json)
 ##   groovy-cmd        = npm-groovy-lint --config "$(groovy-check-conf)"
 ## -----------------------------------------------------------------------
-path-by-makefile = $(strip \
+path-by-makefilepath-by-makefile = $(strip \
   $(foreach filename,$(1),\
     $(foreach makefile,$(lastword $(MAKEFILE_LIST)),\
-    $(foreach makedir,$(subst /include.mk,$(null),$(makefile)),\
-      $(makedir)/$(filename)\
+    $(foreach makedir,$(dir $(makefile)),\
+      $(makedir)$(filename)\
     )\
   ))\
 )
 
+## -----------------------------------------------------------------------
+## Intent: Improve function usability for path-by-makefilepath-by-makefile
+## -----------------------------------------------------------------------
+## Given:
+##   scalar   A makefile variable name to define
+##   scalar   Path within a makefile subdirectory to construct
+## Return:
+##   scalar   Constructed path for the given filename
+## -----------------------------------------------------------------------
+## Usage:
+##   $(call genpath-makefiles,tox-ini,tox.ini)
+##   $(info tox-ini = $(tox-ini))
+## -----------------------------------------------------------------------
+genpath-makefiles = $(strip \
+\
+  $(foreach var,$(1),\
+  $(foreach fyl,$(2),\
+    $(if true$(DEBUG),\
+      $(info $$(eval $(var) := $$(call path-by-makefilepath-by-makefile,$(fyl)))))\
+    $(eval $(var) := $(call path-by-makefilepath-by-makefile,$(fyl)))\
+	))\
+    $(var)\
+)
+
 $(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]