[Breaking] RouteInfo Type And Transition.(from|to)

[chadhietala]

This introduces the public RouteInfo type and from and to fields on the Transition as described in emberjs/rfcs#95.

This PR also:

• [Breaking] removes all underscore methods from the Route type.
• [Breaking] Renames HandlerInfo -> RouteInfo in many places.

[ef4]

It's a big diff and I can't pretend to have followed every bit of it, but it all seems reasonable on first read.

[rwjblue]

How do you plan to mitigate the breakage on the Ember side when we land this there?

[chadhietala]

@rwjblue all of this should absorbed by Ember. With the private infos the only thing that might likely troll users is that I renamed the handle property to route, but other than that the structure should be the same. This is a private API, I can defineProperty and delegate if need be.

[ef4]

This will likely break liquid-outlet. But that’s fine, the whole point was creating public API to replace the private one it’s using