For new installs/downloads, revert to old PD window behavior for now

e.g. docked toolbars, floating windows.  This should make the recent
interface changes *mostly transparent* to established users.

By release time, I anticipate using true single-window mode as the
default.
Fix initial window placement for docked toolbar/floating image situation
Fix docked toolbars incorrectly jumping z-order during main form resizing