Hide drop targets when unit is dropped on a header.
Render token types separately.
Added comments.
Merge pull request #370 from huwshimi/fix-drop-header-hiding

Hide drop targets when unit is dropped on a header

This branch fixes a bug where dropping a unit on a header would leave the drop targets visible.

https://bugs.launchpad.net/juju-gui/+bug/1326240

QA:
- drag a service to the canvas
- open the machine view
- drag a unit to "Create new machine"
- the header should return to "Environment" (with the machine count etc.) and a new machine should be created

Dropping a unit on the containers header should also return the headers to the correct states.
Merge pull request #373 from makyo/token-render

Render token types separately.

Render each token container to the DOM separately for a quick win in speed on loading curated, etc.

QA with the frames timeline, ensure that FPS doesn't drop too far below 15.
Remove initState call for the charmbrowser since it's all handled by the state class now
Merge pull request #376 from hatched/fix-1327424

Remove initState call for the charmbrowser since it's all handled by the state class now

This is the fix for: https://bugs.launchpad.net/juju-gui/+bug/1327424

The initState call was left in the app but it's no longer needed because the charmbrowser controls are all handled directly by the state class.

#### To QA
Click the Juju icon in the to left, no error? OK!