04e28cd7c4
js/ui/calendar.js: Generic calendar widget tests/interactive/calendar.js: Basic test of the calendar js/ui/panel.js: Add a pop-down from the clock that shows a calendar widget. The pop-down is not menu-like to allow the user to interact with an application while looking at the calendar. gnome-shell.css: Add theming for calendar, calendar popup, and for buttons on the panel https://bugzilla.gnome.org/show_bug.cgi?id=596432