A configurable timeline daysback limit

[jonas]

There is currently no top limit on the daysback parameter for the timeline page.
Since timelines for a large number of days can be fairly expensive we need to add a configurable limit with a good default value.

This is something I would like to see go into 0.11 (beta2).

Any objections?

[jonas]

Proposed patch

[cboos]

I'd prefer the default to be unlimited.

Rationale: when one wants to discover a small or moderately sided project using Trac, one would want to see all the project's history at a glance (when did it started, when was the activity period). In this case, giving a high daysback is handy.

If we set the default to limited, I think the above trick won't be doable as people probably won't bother changing the limit up even if their project could afford it.

Other than that I'm OK with the patch (and even for the default settings, I only stated a personal preference, so do as you see fit).

[jonas]

Ok, I've committed it as [6681]. I kept the original default value since I believe it's better to have a safe default value than a convenient but potentially dangerous one.