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_clangd.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+CURRENT_DIR=$(pwd)
+GLOBAL_WORKING_DIR=$(realpath ${CURRENT_DIR}/../..)
+
+# ----------
+
+# make sure the current directory is correct
+if [ ! -d ${CURRENT_DIR}/.templates ] ; then
+	echo "this script should be called by make: make clangd (one level up)"
+	exit 1
+fi
+
+# change / to \/ in paths
+CURRENT_DIR_FOR_SED=$(echo ${CURRENT_DIR} | sed 's/\//\\\//g')
+GLOBAL_WORKING_DIR_FOR_SED=$(echo ${GLOBAL_WORKING_DIR} | sed 's/\//\\\//g')
+
+
+if [ -f "${CURRENT_DIR}/.templates/.clangd" ] ; then
+	if [ ! -f "${CURRENT_DIR}/.clangd" ] ; then
+		cat "${CURRENT_DIR}/.templates/.clangd" | \
+			sed -e "s/%%%CURRENT_DIR%%%/${CURRENT_DIR_FOR_SED}/g" \
+				-e "s/%%%GLOBAL_WORKING_DIR%%%/${GLOBAL_WORKING_DIR_FOR_SED}/g" > \
+			${CURRENT_DIR}/.clangd
+			
+		echo "added a ${CURRENT_DIR}/.clangd file"
+	fi
+fi
+
+