gen_makefile.py: fix echo: add -e to enable backslash escapes

I guess it's enabled by default in some distributions like Debian,
but at least for Arch Linux it needs to be enabled using '-e'.

Change-Id: Ie9c0657c9decb83bf8531ce1a0e97c27ee7008bb

gen_makefile.py

@@ -171,21 +171,21 @@ def gen_make(proj, deps, configure_opts, jobs, make_dir, src_dir, build_dir, url
 {proj}_files := $(shell find {src_proj} -name "*.[hc]" -or -name "*.py" -or -name "*.cpp" -or -name "*.tpl" -or -name "*.map")
 
 .make.{proj}.clone:
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	test -d {src} || mkdir -p {src}
 	test -d {src_proj} || ( git -C {src} clone "{url}/{proj}" "{proj}" && git -C "{src}/{proj}" remote set-url --push origin "{push_url}/{proj}" )
 	sync
 	touch $@
 
 .make.{proj}.autoconf: .make.{proj}.clone {src_proj}/configure.ac
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	-rm -f {src_proj}/.version
 	cd {src_proj}; autoreconf -fi
 	sync
 	touch $@
 	
 .make.{proj}.configure: .make.{proj}.autoconf {deps_installed} $({proj}_configure_files)
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	-chmod -R ug+w {build_proj}
 	-rm -rf {build_proj}
 	mkdir -p {build_proj}
@@ -194,13 +194,13 @@ def gen_make(proj, deps, configure_opts, jobs, make_dir, src_dir, build_dir, url
 	touch $@
 
 .make.{proj}.build: .make.{proj}.configure $({proj}_files)
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	$(MAKE) -C {build_proj} -j {jobs} {check}
 	sync
 	touch $@
 
 .make.{proj}.install: .make.{proj}.build
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	{sudo_make_install}$(MAKE) -C {build_proj} install
 	{no_ldconfig}{sudo_ldconfig}ldconfig
 	sync
@@ -215,7 +215,7 @@ def gen_make(proj, deps, configure_opts, jobs, make_dir, src_dir, build_dir, url
 
 .PHONY: {proj}-clean
 {proj}-clean:
-	@echo "\n\n\n===== $@\n"
+	@echo -e "\n\n\n===== $@\n"
 	-chmod -R ug+w {build_proj}
 	-rm -rf {build_proj}
 	-rm -rf .make.{proj}.*