[Bug 857153] Add data bucketing to rickshaw_utils.

This gives the ability to reduce time regions in buckets to make things a little cleaner to analyze on the large scale. The reduction method defaults to simple sum, but can be configured to average for things like percentage lines.
    
There are also tweaks to the set and line system to make this all work together, and there is a very useful update method on Graphs now which redraws the graph in a pretty reliable way.

I also swapped out rickshaw.min.js for rickshaw.js (in a separate commit), because we minify it anyways, and this makes debugging *way* easier.