Automatic resolution of latest and recommended forge builds.

You can now use 'latest' or 'recommended' as the forge version option in the generate commands.
Two new commands are provided to query the latest/recommended version of forge.

src/model/forge/promotionsslim.ts

@@ -0,0 +1,8 @@
+export interface PromotionsSlim {
+
+    homepage: string
+    promos: {
+        [id: string]: string
+    }
+
+}