Add a NoCache setting

Added this to the settings so it can be configured at runtime.  If set
to true, a Cache-Control header will be sent with the wasm file as well
as the index html.

handlers.go

@@ -63,7 +63,9 @@ func wsStaticFiles(w http.ResponseWriter, r *http.Request) {
 }
 
 func wsWasmFile(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+	if settings.NoCache {
+		w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+	}
 	http.ServeFile(w, r, "./static/main.wasm")
 }
 
@@ -215,7 +217,9 @@ func handleIndexTemplate(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Force browser to replace cache since file was not changed
-	w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+	if settings.NoCache {
+		w.Header().Set("Cache-Control", "no-cache, must-revalidate")
+	}
 
 	err = t.Execute(w, data)
 	if err != nil {

settings.go

@@ -32,6 +32,9 @@ type Settings struct {
 	Bans            []BanInfo
 	LogLevel        common.LogLevel
 	LogFile         string
+
+	// Send the NoCache header?
+	NoCache bool
 }
 
 type BanInfo struct {