new 'add()' and 'update()' functions

the 'add()' function takes an object and pushes it to the circle's
data array and then appends the html element.

the 'update()' function can be run after the user has added data to
the circle's data array. running 'update()' will append the html elments.
Merge branch 'master' of https://github.com/dakridge/CircularJS