Enhance shellcheck lint target (2 of 3 -- installer)

makefiles/lint/shell/help.mk
----------------------------
  o Top level include used to source all lint-shell library makefiles.
  o Loosely based on makefiles/{groovy,doc8}/*.
  o Currently library makefile makefiles/shell.mk deprecation pending.
  o Prefix yet-to-be-added makefile includes with hyphen to prevent errors.

makefiles/lint/shell/install.mk
-------------------------------
  o Adding a tool makefile for installing shellcheck via dependency.
  o NOP if shellcheck exists else install the latest v0.9.0.
  o Added library target lint-shell-cmd-version
    - Dependency for lint-shell-* makefile targets
    - Used for central logging to display shellcheck command in use.
  o lint-shell-install
    - Install makefile target is dependency driven.
    - Prefer system installed command with fallback to installation
      of the 'latest' shellcheck version v0.9.0.

Unit testing:
  - mkcheck.sh script will setup a usable sandbox to try out
    lint-shell makefile targets.

https://wiki.opennetworking.org/display/VOLTHA/repo%3Aonf-make

Change-Id: Ica33f4c2c01cd63bc400a7db3c1e299cbcc030e7
diff --git a/makefiles/lint/shell/include.mk b/makefiles/lint/shell/include.mk
index 63797d5..293947f 100644
--- a/makefiles/lint/shell/include.mk
+++ b/makefiles/lint/shell/include.mk
@@ -21,7 +21,7 @@
 ##---]  INCLUDES  [---##
 ##--------------------##
 -include $(ONF_MAKEDIR)/lint/shell/help.mk
--include $(ONF_MAKEDIR)/lint/shell/install.mk
+include $(ONF_MAKEDIR)/lint/shell/install.mk
 include $(ONF_MAKEDIR)/lint/shell/shellcheck.mk
 
 $(if $(DEBUG),$(warning LEAVE))