view: Add tree view and selection handling
view: Rename Done button to Cancel and remove emphasis
view: Add selection toolbar
stack: Code cleanup in pop()

Remove unused variable. Add a variable for the old page.
Update libgd submodule
view: Fix selection mode still enabled after toggling

Make binding of selection-mode-enabled and "active" property of Select
button bidirectional.
view: Add Delete button to selection toolbar
view: Remove overlay

The selection toolbars are no longer on-screen display widgets, so this is
no longer needed.
window: Add overlay on top of stack

This is needed by the notifications.
view: Add method select_all
view: Add select menu button when in selection mode
Add vapi for gd-1.0 instead of building at runtime
Port to GTK+ 3.10
view: Add search button and bar
src/Makefile: Target glib 2.38 and link resources

This is needed for porting widgets to use GTK+ Templates.
window: Port to GTK+ Template
date-entry: Port to GTK+ Template
view: Port to GTK+ Template
view: Add signal search-changed
view: Add new property search-mode-enabled