all: Store assets as strings (#6611)

Storing assets as []byte requires every compiled-in asset to be copied
into writable memory at program startup. That currently takes up 1.6MB
per syncthing process. Strings stay in the RODATA section and should be
shared between processes running the same binary.

script/genassets.go

@@ -29,8 +29,8 @@ package auto
 
 const Generated int64 = {{.Generated}}
 
-func Assets() map[string][]byte {
-	var assets = make(map[string][]byte, {{.Assets | len}})
+func Assets() map[string]string {
+	var assets = make(map[string]string, {{.Assets | len}})
 {{range $asset := .Assets}}
 	assets["{{$asset.Name}}"] = {{$asset.Data}}{{end}}
 	return assets
@@ -72,7 +72,7 @@ func walkerFor(basePath string) filepath.WalkFunc {
 			name, _ = filepath.Rel(basePath, name)
 			assets = append(assets, asset{
 				Name: filepath.ToSlash(name),
-				Data: fmt.Sprintf("[]byte(%q)", buf.String()),
+				Data: fmt.Sprintf("%q", buf.String()),
 			})
 		}