Minor edits to support repo:onf-make

Makefile
--------
  o Remove Makefile inlined include help/trailer.mk, lib sourced.

lf/include.mk
-------------
  o Mark git-submodule targets as .PHONY so they always process.
  o Use library $(banner) macro to annouce target for logging.
  o Add help text for two git-submodule targets.

requirements.txt
----------------
  o Add bashate to the list of python modules to install.

Change-Id: If35c7aac9e0deb25c0fc0ba8b158aafe78d6754f
diff --git a/requirements.txt b/requirements.txt
index 23e849d..7b561ae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,6 +6,8 @@
 pipdeptree
 jenkins-jobs
 
+bashate
+
 # Installed on-demand by makefiles/lint/python/{flake8,pylint,tox}.mk
 # pylint
 # tox