add a clangd and qtcreator make targets

Add a clangd make target:
$ make clangd
This installs a .clangd file with configuration (includes/macros/compiler flags)
for the clandg language server.

Add a qtcreator make target:
$ make qtcreator
This installs a .qtcreator directory with QTCreator IDE project files.
In the QTCreator you can open a project by selecting the .qtcreator/ezc.creator
file.

You can use 'make qtcreator' again to refresh .qtcreator/ezc.files,
the rest of the project files will not be modified.

.templates/install_qtcreator.sh

@@ -0,0 +1,65 @@
+#!/bin/sh
+
+CURRENT_DIR=$(pwd)
+GLOBAL_WORKING_DIR=$(realpath ${CURRENT_DIR}/..)
+QTCREATOR_DIR=${CURRENT_DIR}/.qtcreator
+
+# ----------
+
+# make sure the current directory is correct
+if [ ! -d ${CURRENT_DIR}/.templates ] ; then
+	echo "this script should be called by make: make qtcreator (one level up)"
+	exit 1
+fi
+
+# change / to \/ in paths
+CURRENT_DIR_FOR_SED=$(echo ${CURRENT_DIR} | sed 's/\//\\\//g')
+GLOBAL_WORKING_DIR_FOR_SED=$(echo ${GLOBAL_WORKING_DIR} | sed 's/\//\\\//g')
+
+was_qtcreator_dir=0
+
+if [ -d "${QTCREATOR_DIR}" ] ; then
+	was_qtcreator_dir=1
+else
+	mkdir -p "${QTCREATOR_DIR}"
+fi
+
+if [ -d "${QTCREATOR_DIR}" ] ; then
+
+	if [ -d ${CURRENT_DIR}/.templates/.qtcreator ] ; then
+		cd ${CURRENT_DIR}/.templates/.qtcreator
+		
+		if [ $? -eq 0 ] ; then
+
+			for i in * ; do
+				if [ ! -f "${QTCREATOR_DIR}/$i" ] ; then
+					cat "$i" | \
+						sed -e "s/%%%CURRENT_DIR%%%/${CURRENT_DIR_FOR_SED}/g" \
+							-e "s/%%%GLOBAL_WORKING_DIR%%%/${GLOBAL_WORKING_DIR_FOR_SED}/g" > \
+						"${QTCREATOR_DIR}/$i"
+				fi
+			done
+
+			if [ $was_qtcreator_dir -eq 0 ] ; then
+				echo "QTCreator files generated to ${QTCREATOR_DIR} directory"
+				echo "select an 'open project...' option and find a ${QTCREATOR_DIR}/*.creator file"
+			fi
+
+		fi
+	fi
+
+
+	find ${QTCREATOR_DIR} -name "*.files" | while read projectfiles ; do
+	
+		cd ${CURRENT_DIR}/src
+		
+		if [ $? -eq 0 ] ; then
+			find ../src -type f \( -iname "*.cpp" -o -iname "*.h" \) | sort > ${projectfiles}
+			echo "file ${projectfiles} has been updated"
+		fi
+
+	done
+
+fi
+
+