added names to selected hackers
HTML/CSS changes
Refactoring

Moved code for producing array of top languages into a separate
function.
Major refactoring

Separate functions `SelectHacker`, `drawLinks` and `drawNodes`.

These use accessor functions `xfunc` and `yfunc` to retrive the
coordinates from data items. This means the axis can be changed without
modifiying the JSON data file.

The links are now just objects holding `source` and `target` identifiers
rather than the coordinates.
Selecting a hacker displays them at the top
Changed how `data.links` is created

It now included the weight of each links.
Added buttons to change coordinate sets
Principle components default to possitive
Corrected onclick for hacker images

Both the hacker images and collaborator images are refreshed when
switching between plots.

The second plot now shows total collaboration versus collaboration with
hacker schoolers.
Updated README.md
Added lables to chart
deleted old files
renamed files
Merged changes from Chris Edgemon

In particular:

Add other classes, residents, instructors to hacker_school.py; modify
scrape.py code accordingly.

Correct spelling of requirments.txt; add ~ to .gitignore.
Pull group scraping logic out of if __name__ block and clean up.
Merge pull request #2 from chirs/master

Pull scrape code out of if __name__ == __Main__
Moved files for compatibility with Github Pages
Remove duplicate SVG element

This was causing issues in Firefox.
updated README
Change link from https to http.