Porting PagedView from KG to gain simplified scaling model, reordering

-> We are no longer scaling individual Celllayouts, instead we are scaling
   the entire Workspace (and the CellLayouts come along for the ride)
-> Due to the above change, many assumptions were broken. In particular,
   our drag and drop / animation archiecture is fairly fragile due to the
   frequent and complex mapping of points between different bits of the
   hierarchy. This CL contains a number of fixes which address such
   breakages.

Change-Id: I2e630eab17528729b764b61f587858f6499fd318
13 files changed