Land Sysprof 2.x

This is a major redesign a modernization of Sysprof. The core data
structures and design are largely the same, but it has been ported to
Gtk3 and has lots of additions that should make your profiling experience
smoother. Especially for those that are new to profiling.

There are some very simple help docs added, but we really need the
experts to come in and write some documentation here.

src/resources/theme/shared.css

@@ -0,0 +1,12 @@
+popover list row {
+  padding: 6px 10px 6px 10px;
+  border-bottom: 1px solid alpha(@borders, 0.2);
+}
+
+popover list row:last-child {
+  border-bottom: none;
+}
+
+popover scrolledwindow {
+  border-top: 1px solid alpha(@borders, 0.75);
+}