Promise can't be its own parent or child

RSVP currently chains a promise onto itself as a form of optimization.
This causes infinite recursion during instrumentation.

Current workaround is to just ignore this type of chaining, until a more
permanent fix is in place.

Fixes #204
Reduce render performance overhead by instrumenting out of band

Fixes #197
Send view tree and current route out of band

Fixes #197
Add split-view styles and markup inspired by Chrome dev tools
Redesign main nav and model types nav to be consistent with Chrome dev tools
Add sidebar-toggle component
Improve drag-handle component
Add resizable-column component
Render toolbars in routes using TabRoute
Improve consistency of toolbar components
Simplify notice styles
Rename .split-view to just .split
Redesign object inspector to be consistent with Chrome dev tools
Merge pull request #206 from domchristie/dev-tools-layout

Consistency with Chrome Dev Tools
Bump version to 1.5.0