Support additional screen layouts.

Allows users to choose a single screen layout or a large screen layout.
Adds a configuration option to change the prominent screen.

src/common/CMakeLists.txt

@@ -5,6 +5,7 @@ set(SRCS
             break_points.cpp
             emu_window.cpp
             file_util.cpp
+            framebuffer_layout.cpp
             hash.cpp
             key_map.cpp
             logging/filter.cpp
@@ -35,6 +36,7 @@ set(HEADERS
             common_types.h
             emu_window.h
             file_util.h
+            framebuffer_layout.h
             hash.h
             key_map.h
             linear_disk_cache.h