Move organization chart into team structure page

This is a first pass at closing #833 (closed).

The organization chart previously generated by Google Charts has been replaced with a simple CSS/HTML solution that renders largely the same as before. The chart has been moved into the team structure page, replacing the vertical list that used to be there.

Screen shot:

Concerns:

• Currently a webkit hack is employed in order to prevent the scroll bar from auto-hiding in OSX, but there doesn't seem to be a similar solution for Firefox. This has not been tested on Windows or IE/Edge.
• The team structure list being replaced with this org chart had a lot of helpful links to the handbook as well as to job openings which are missing from this chart.

Future considerations:

• Eventually, this chart should be made compact and responsive. Nodes that are three levels deep or more should be collapsed into vertical lists to prevent an extremely long scrollbar.
• CSS media queries can be used to automatically convert this horizontal chart back into a vertical list on mobile devices (since underneath everything it is simply <ul /> and <li /> elements.