[REF] config: move mode from owl.__info__ to owl.config

and move it to its own file.

src/config.ts

@@ -0,0 +1,31 @@
+import { QWeb } from "./qweb/index";
+
+/**
+ * This file creates and exports the OWL 'config' object, with keys:
+ *  - 'mode': 'prod' or 'dev',
+ */
+
+interface Config {
+  mode: string;
+}
+
+const _config:Partial<Config> = {};
+
+Object.defineProperty(_config, "mode", {
+  get() {
+    return QWeb.dev ? "dev" : "prod";
+  },
+  set(mode: string) {
+    QWeb.dev = mode === "dev";
+    if (QWeb.dev) {
+      const url = `https://github.com/odoo/owl/blob/master/doc/tooling.md#development-mode`;
+      console.warn(
+        `Owl is running in 'dev' mode.  This is not suitable for production use. See ${url} for more information.`
+      );
+    } else {
+      console.log(`Owl is now running in 'prod' mode.`);
+    }
+  },
+});
+
+export const config:Config = _config as Config;