Add support for a Layout controller to work with dojox/mobile/FixedSplitter and ScreenSizeAware.

[edchat]

Currently the way the domNodes are being appended in main.js and View.js do not allow the Layout controller to support dojox/mobile/FixedSplitter and ScreenSizeAware.

[edchat]

See this link for more details in the 1.9 plan doc.
https://docs.google.com/document/d/1fe2qm1x_AHidYd2wNkG77tZgFIrvlt-ctGT0rpb-5F0/edit?pli=1#heading=h.o1ba3w9d6miu

Layout controller is not really replaceable, it is tight with code in View.js and main.js. It must be made totally independent and replaceable.

Ideally one must be able to use a ScreenSizeAware layout (extracted from dojox/mobile to make it available to multichannel) and thus use a single layout for all devices.

If not successful a more dojox/app-specific flexible default layout must be introduced which would allow to re-use a phone view as the left view of the tablet.

In any case in order to enable the kind of composite views a desktop app requires, more flexibility is required for child view regions - e.g. perhaps giving the parent the ability to specify "openings" or regions where children views would be put.