D3 is missing some methods on the Transition interface

This commit adds 3 of the missing methods - each(), transition() and ease().

It also updates the test with the Chained Transitions example from http://bl.ocks.org/mbostock/1125997

I've run the test with:
node ../_infrastructure/tests/typescript_0.8.3/tsc.js d3-tests.ts --out d3-tests.js

Hope that's the correct way to do it?