stack: Add Back button
window: Remove Back button

Moved it to Stack.
stack: Add property to hide the Back button
stack: Allow pop of last item
view: Hide close button on selection mode
view: Correct comment on search mode binding
view: Enable selection mode on right-click

Right-click will work like left-click if selection mode is enabled.
view: Disable selection mode if enabled when hidden
view: Clear search text when search mode is enabled
view: Set custom title of header as property

This is to remove a compiler warning. The setter function for custom
title is not properly annotated.
stack: Set custom title of header as property

This is to remove a compiler warning. The setter function for custom
title is not properly annotated.
date-entry: Destroy popup when a day is clicked

Instead of setting visibility when the arrow button is toggled, create
a new one everytime the button is active, then destroy it when the
button loses focus, the button becomes inactive, or a day is selected.