The layout class is the only class that should have knowledge of
page-level constant markup, such as #gutter and #contacts, and
should be pretty much the only place we find elements by id (with
the exception of template elements).
This change removes references to #gutter from views. Rather than
hardcoding assumptions about page layout, view elements should
ask the layout to insert themselves into the main content area by
calling Whisper.Layout.setContent.