Update to 20180724 release.

byuu says:

I failed to complete a WIP, have five of eight cores updated with some
major changes to Emulator::Interface. I'll just post a quick temporary
WIP in the off chance someone wants to look over the new interface and
comment on it.

Also implemented screen saver suppression into hiro/GTK.

I should also add ... a plan of mine is to develop target-bsnes into a
more generic user interface, with the general idea being that
target-higan is for multiple Emulator::Interface cores at the same time,
and target-bsnes is for just one Emulator::Interface core.

The idea being that if one were to compile target-bsnes with the GBA
core, it'd become bgba, for instance.
I don't plan on releasing single-core emulators like this, but ... I don't see any downsides to being more flexible.

hiro/core/desktop.hpp

@@ -0,0 +1,8 @@
+#if defined(Hiro_Desktop)
+struct Desktop {
+  Desktop() = delete;
+
+  static auto size() -> Size;
+  static auto workspace() -> Geometry;
+};
+#endif