Make it possible to set default card values

This is a big bunch of commits taken from @iwooten in #75 and then some cleaning up by me.

With this PR, we allow the initial values of the rendered Card to be arbitrarily set. We also move setting the initial value of the name field from `fullName` in the `options.messages` object to `name` in the `options.values` object.

/cc @iwooten @luanmuniz @JacquesLoubser @saygun