Version 0.2 Release Candidate

This is a pretty big rewrite of SnakeViz mostly with the goal of improving performance. I've thrown a large and detailed profile at this version and it seems to work just fine, so I'm hoping this will be eliminate the performance issues we all had with version 0.1. Please take this for a spin and leave any feedback here.

The big, high level changes are:

- Do minimal pre-processing of stats in Python, then embed the data in the HTML for use by the client code
- Do all of the function call-tree building in the client
- Limit the depth of the displayed call tree (depth defaults to 10)
- Filter out arcs that would be too small to see (reduces the number of elements in the SVG)

Other, smaller changes include:

- On-demand view of the current call stack (the stack to the current center of the sunburst)
- No more tooltips, function info is displayed to the side of the sunburst

Screenshot of the new stuff in action:

![screen shot 2014-11-20 at 11 40 17 am](https://cloud.githubusercontent.com/assets/920492/5138319/1151d2b2-7102-11e4-8562-4f0c8c117aaf.png)

The call stack collapses so it won't always cover the sunburst.