Incorporate the whitespace linter from the CTL project

This just brings over the whitespace linter and updates any
files that may have been out of compliance.  It's also a small
update to .gitignore to not care about the .out files generated
by a make cover command.

Change-Id: I3e5a4f170f0fd7724949708a290a1e13def834fb

.gitignore

@@ -1,5 +1,5 @@
 # Coverage File
-coverage.out
+*.out
 tools/bin
 tools/*node*
 

Makefile

@@ -154,9 +154,16 @@ docs:
 
 .PHONY: lint
 lint: tidy $(LINTER) $(NPX)
+	@echo "Performing linting steps..."
+	@echo "Running whitespace linting step..."
+	@./tools/whitespace_linter
+	@echo "Running golangci-lint linting step..."
 	$(LINTER) run --config $(LINTER_CONFIG)
+	@echo "Running eslint for JavaScript linting step..."
 	cd $(WEBDIR) && (PATH="$(PATH):$(JSLINTER_BIN)"; $(NPX) --no-install eslint js) && cd ..
+	@echo "Running eslint for HTML linting step..."
 	cd $(WEBDIR) && (PATH="$(PATH):$(JSLINTER_BIN)"; $(NPX) --no-install eslint --ext .html .) && cd ..
+	@echo "Linting completed successfully"
 
 .PHONY: tidy
 tidy:

tools/whitespace_linter

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+# git 1.9.0+ allows for exclusions in pathspecs via ':!foo' syntax.
+# However, until git 2.13.0 there must be at least one "inclusive" pathspec, hence the './*'
+trailing_whitespace=$(git grep -E -n -- ' +$' -- './*' ':!*.png' ':!*.jpg')
+
+if [[ -n "$trailing_whitespace" ]]; then
+  printf "ERROR: Trailing whitespaces:\n"
+  awk 'BEGIN {FS=":"} {printf " * %s:%s\n", $1, $2}' <<< "$trailing_whitespace"
+  exit 1
+fi