Update samples to use 'bounds' parameter to window.create.

Older parameters of left, top, widgth, height have been deprecated.
This clean up is part of http://crbug.com/181651, fixing documentation
to use app.window.create({ bounds: {left, top, width, height}}).
Merge pull request #73 from scheib/window-create-size-

Update samples to use 'bounds' parameter to window.create.