Including gitCommit and version in frontend build. Backend now sending a backendInfo object containing commit, version and hostname. All printed on About page.

backend/src/mempool.interfaces.ts

@@ -160,3 +160,9 @@ interface RequiredParams {
 
 export interface ILoadingIndicators { [name: string]: number; }
 export interface IConversionRates { [currency: string]: number; }
+
+export interface IBackendInfo {
+  hostname: string;
+  gitCommit: string;
+  version: string;
+}