This commit provides a standard interface for time intervals:
interval.floor(date)
interval.ceil(date)
interval.offset(date, k)
interval.range(start, stop, step)
All local-time intervals (such as d3.time.day) have a UTC-equivalent interval,
available as interval.utc (such as d3.time.day.utc).
Fixes#463. Note that for the time.scale, an interval function is required to
nice (such as d3.time.day). In the future, we might relax that to allow a count
of ticks, similar to the ticks method, but in that case we'd also need the
ability to floor to a given tick number (e.g., every other week) and likewise
for ceil. This seems like a reasonable first implementation.
Rather than producing separate files for each module, the default build now
produces a single file. This should encourage better page-load performance as
the files were relatively small. Also, it's easier to deal with only one file
rather than many, especially if you're not quite sure what the dependencies are.
You may still create minimized builds, if you don't want every feature.
This commit also demotes the chart components to the examples directory, rather
than keeping them as part of the core library. As always, D3 is not a charting
library, and these were ever only intended to serve as examples.
Mike Bostock