Angular 6 support

[jscharett]

I believe Angular 6 supports RXJS version 6 which uses a different import syntax; at least that's what I was reading. If true, some changes will likely need to be made to support. Adding issue for tracking purposes.

[RobYed]

@mkowalzik I would like to migrate the RxJS related stuff to the new pipe and let syntax. This would imply that RxJS version >= 5.5.x is mandatory. This is by default the case since Angular 5.0.x. What is our support regarding the Angular version?