Filter in dashboard should overwrite filter in question.

Hi,

First i want to say that the dashboard filters feature looks awesome ! Well done !!

However I realised that to make the daterange filter work you have to remove the filter on timestamp that is in saved question. I think it should overwrite it instead.
The other problem is that because you have to remove them it forces you to make a query on all the data which can be a problem for the database.

Again really great piece of work !

Cheers
Younes

Reproduce a dashboard date-range filter against a saved question that already has a timestamp filter, then trace the dashboard filter and query integration points. Done means the dashboard filter overrides the saved question filter and does not require querying all data after removing the original constraint.

Written by the indexing model from the issue text.