Use printf for generating version.go (#933)

Flag -e is to "enable interpretation of backslash escapes"
Which might be a default, depends on a shell.

`sh -c 'echo "a\nb"'` on my OS prints
> a\nb

(no newline)

## Launch Checklist

<!-- Thanks for the PR! Feel free to add or remove items from the
checklist. -->
 - [x] Briefly describe the changes in this PR.

desktop/Makefile

@@ -32,9 +32,9 @@ $(GOBIN)/rice:
 # Embed the current version number in the executable by writing version.go
 .PHONY: version.go
 version.go:
-	@echo "// DO NOT EDIT: Autogenerated by Makefile\n" > version.go
-	@echo "package main\n" >> version.go
-	@echo "const Version = \"$(VERSION)\"" >> version.go
+	@printf "// DO NOT EDIT: Autogenerated by Makefile\n" > version.go
+	@printf "package main\n" >> version.go
+	@printf "const Version = \"$(VERSION)\"\n" >> version.go
 
 rice-box.go: $(GOBIN)/rice editor/pull_release
 	$(GOBIN)/rice embed-go

src/components/ModalSources.tsx

@@ -155,7 +155,7 @@ class AddSource extends React.Component<AddSourceProps, AddSourceState> {
     }
     case 'tile_raster': return {
       type: 'raster',
-      tiles: (source as RasterSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.pbf`],
+      tiles: (source as RasterSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
       minzoom: (source as RasterSourceSpecification).minzoom || 0,
       maxzoom: (source as RasterSourceSpecification).maxzoom || 14,
       scheme: (source as RasterSourceSpecification).scheme || 'xyz',
@@ -167,7 +167,7 @@ class AddSource extends React.Component<AddSourceProps, AddSourceState> {
     }
     case 'tilexyz_raster-dem': return {
       type: 'raster-dem',
-      tiles: (source as RasterDEMSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.pbf`],
+      tiles: (source as RasterDEMSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
       minzoom: (source as RasterDEMSourceSpecification).minzoom || 0,
       maxzoom: (source as RasterDEMSourceSpecification).maxzoom || 14,
       tileSize: (source as RasterDEMSourceSpecification).tileSize || 512