Arjen time window get data

### Problem
after refactoring:
* requests didn't pass start, stop and aggregation window arguments anymore.
* timeline directive was in limbo state with watches watching the wrong state parameters and triggering getData function with wrong parameters.
* rain template was build on changed data containers.

### Solution
* pass start, stop and aggregation window with point and area requests
* fix timeline-directive so watchers watch the proper state and request for cumulative rain data gets passed proper layer
* fix rain template to read data from point model on scope for point intersection of rain and rain recurrence time

*NOTE:* had to add extra option to backend layer definition `rrc` for layer aggregation type.