fix(Cron Parser): handle aws, next executions and TZ

Handle AWS Cron syntax and distinguishe from standard syntax (fix #855)
Add show crontab next 5 execution times (taken from #1283)
Add Timezone handling: fix #261

src/tools/crontab-generator/get-timezone-offset.d.ts

@@ -0,0 +1,3 @@
+declare module "get-timezone-offset" {
+    export default function(timeZoneName: string, date: Date);
+}