Add commit to external stylesheet url (#12902)

- currently only the release is used as a fingerprint which produces
  caching issues for all lastest master builds
- also add build commit to url fingerprint
- make bra also watch go html template files

.bra.toml

@@ -9,7 +9,7 @@ watch_dirs = [
 	"$WORKDIR/public/views",
 	"$WORKDIR/conf",
 ]
-watch_exts = [".go", ".ini", ".toml"]
+watch_exts = [".go", ".ini", ".toml", ".template.html"]
 build_delay = 1500
 cmds = [
   ["go", "run", "build.go", "-dev", "build-server"],

public/views/index.template.html

@@ -11,7 +11,7 @@
 
   <base href="[[.AppSubUrl]]/" />
 
-  <link rel="stylesheet" href="public/build/grafana.[[ .Theme ]].css?v[[ .BuildVersion ]]">
+  <link rel="stylesheet" href="public/build/grafana.[[ .Theme ]].css?v[[ .BuildVersion ]]+[[ .BuildCommit ]]">
 
   <link rel="icon" type="image/png" href="public/img/fav32.png">
   <link rel="mask-icon" href="public/img/grafana_mask_icon.svg" color="#F05A28">