react-with-addons build

This creates a new standalone build which should have everything the
default build has, plus a little extra. This is not a sustainable long
term solution (we shouldn't make people choose like this) but it fixes
the problem we have in the short term.

This also removes the terrible react-transitions build. This is better
anway.

Fixes #369
Make sure addons builds are sent to build server
Make sure react-with-addons ends up in bower
Make sure react-with-addons ends up in react-source gem
Add TransitionGroup example
Merge pull request #370 from zpao/addons

react-with-addons build