Fix for #828: Embed build tags (#1051)

* Fix for #828
Add build tags to ldflags and print in version output

Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Reworked formatBuiltWith function

Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Add tags to version information in admin panel

Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Added new variable for use on admin page.

Signed-off-by: Jonas Östanbäck <jonas.ostanback@gmail.com>

* Fixed incorrect indentation

main.go

@@ -8,6 +8,7 @@ package main // import "code.gitea.io/gitea"
 
 import (
 	"os"
+	"strings"
 
 	"code.gitea.io/gitea/cmd"
 	"code.gitea.io/gitea/modules/log"
@@ -18,15 +19,19 @@ import (
 // Version holds the current Gitea version
 var Version = "1.1.0+dev"
 
+// Tags holds the build tags used
+var Tags = ""
+
 func init() {
 	setting.AppVer = Version
+	setting.AppBuiltWith = formatBuiltWith(Tags)
 }
 
 func main() {
 	app := cli.NewApp()
 	app.Name = "Gitea"
 	app.Usage = "A painless self-hosted Git service"
-	app.Version = Version
+	app.Version = Version + formatBuiltWith(Tags)
 	app.Commands = []cli.Command{
 		cmd.CmdWeb,
 		cmd.CmdServ,
@@ -41,3 +46,11 @@ func main() {
 		log.Fatal(4, "Failed to run app with %s: %v", os.Args, err)
 	}
 }
+
+func formatBuiltWith(Tags string) string {
+	if len(Tags) == 0 {
+		return ""
+	}
+
+	return " built with: " + strings.Replace(Tags, " ", ", ", -1)
+}