Changed heights of body parts to percentages of total height rather than fixed. Updated demo to show stick-persons of different heights.

Added javascript to set a default height when none is given.

Added javascript to set width relative to height so head is always circular.

R=alancutter@chromium.org

Review URL: https://codereview.appspot.com/51110043
Merge remote-tracking branch 'origin/master' into HEAD
Update components.