Replace echo -e with printf in scripts

echo -e is not POSIX compliant, and as we have to use #!/bin/sh shebang
line, echo might very well be unaware of "-e" argument. Therefore we
replace it with printf.

devTools/concatFiles.sh

@@ -8,6 +8,6 @@ rm -f "$3"
 files=$(find "$1" -name "$2" -print)
 files=$(echo "$files" | sort)
 for f in $files; do
-	echo -e "\n/* ${f#$1} */\n" >> "$3"
+	printf "\n/* ${f#$1} */\n" >> "$3"
 	cat "$f" >> "$3"
 done

devTools/makeTwineCSSPassage.sh

@@ -10,7 +10,7 @@ collectCSSForTwine() {
 	files=$(echo "$files" | sort)
 	echo "" > "$2"
 	for f in $files; do
-		echo -e "\n/* ${f} */\n" >> "$2"
+		printf "\n/* ${f} */\n" >> "$2"
 		cat "$f" >> "$2"
 	done
 }

devTools/makeTwineJSPassage.sh

@@ -10,7 +10,7 @@ collectJSForTwine() {
 	files=$(echo "$files" | sort)
 	echo "" > "$2"
 	for f in $files; do
-		echo -e "\n/* ${f} */\n" >> "$2"
+		printf "\n/* ${f} */\n" >> "$2"
 		sed -nf "$1"/devTools/stripComments.sed "$f" >> "$2"
 	done
 }