`generateWithTime` from `rx.lite.d.ts` was renamed to `generateWithRelativeTime` and moved as common part to `rx.time-lite.ts`.
Added Rx.helpers functions.
Added overloads of `defer` and `catch`/`catchException` with handle promises.
Version bump to 2.2.18
Merge branch 'RxJS-2.2.18'
Merge pull request #1962 from Igorbek/master

RxJS: updated to version 2.2.18