Fix makefile compat with macOS

The BSD /bin/echo doesn't know the option '-e'

Makefile

@@ -42,13 +42,13 @@ $(CACHE_DIR):; @mkdir -p $(CACHE_DIR)
 %_handout.pdf: %.tex $(wildcard *.bib) $(PACKAGE_TGT) $(CACHE_DIR)
 	@cd $(dir $< ) && $(COMPILE_TEX) -jobname=$*_handout $(notdir $<)
 	@cp $(CACHE_DIR)/$(notdir $@) $@
-	@test ! -f $@pc -a -f $(CACHE_DIR)/$(notdir $@)pc && ( /bin/echo -e "[file]\n$@\n[font_size]\n$(PDFPC_SIZE)" ; cat $(CACHE_DIR)/$(notdir $@)pc | sed 's/\\\\/\n/g' | sed 's/\\par/\n\n/g' ) > $@pc || echo "ignoring PDFPC file" && exit 0
+	@test ! -f $@pc -a -f $(CACHE_DIR)/$(notdir $@)pc && ( /bin/echo "[file]"; /bin/echo "$@"; /bin/echo "[font_size]"; /bin/echo "$(PDFPC_SIZE)"; cat $(CACHE_DIR)/$(notdir $@)pc | sed 's/\\\\/\n/g' | sed 's/\\par/\n\n/g' ) > $@pc || echo "ignoring PDFPC file" && exit 0
 
 
 %.pdf: %.tex $(wildcard *.bib) $(PACKAGE_TGT) $(CACHE_DIR)
 	@cd $(dir $< ) && $(COMPILE_TEX) $(notdir $<)
 	@cp $(CACHE_DIR)/$(notdir $@) $@
-	@test ! -f $@pc -a -f $(CACHE_DIR)/$(notdir $@)pc && ( /bin/echo -e "[file]\n$@\n[font_size]\n$(PDFPC_SIZE)" ; cat $(CACHE_DIR)/$(notdir $@)pc | sed 's/\\\\/\n/g' | sed 's/\\par/\n\n/g' ) > $@pc || echo "ignoring PDFPC file" && exit 0
+	@test ! -f $@pc -a -f $(CACHE_DIR)/$(notdir $@)pc && ( /bin/echo "[file]"; /bin/echo "$@"; /bin/echo "[font_size]"; /bin/echo "$(PDFPC_SIZE)"; cat $(CACHE_DIR)/$(notdir $@)pc | sed 's/\\\\/\n/g' | sed 's/\\par/\n\n/g' ) > $@pc || echo "ignoring PDFPC file" && exit 0
 
 preview-%: %.tex $(wildcard *.bib) $(PACKAGE_TGT) $(CACHE_DIR)
 	@cd $(dir $< ) && $(COMPILE_TEX) $(notdir $<) -pvc -interaction=nonstopmode -view=pdf