Simplifying exception handling (via ReportException) and generalizing Display to fall back to console output when Qt5 was not incorporated

--HG--
rename : include/elemental/graphics.hpp => include/elemental/io.hpp
rename : include/elemental/graphics/ColorMap.hpp => include/elemental/io/ColorMap.hpp
rename : include/elemental/graphics/Display.hpp => include/elemental/io/Display.hpp
rename : include/elemental/graphics/Spy.hpp => include/elemental/io/Spy.hpp
rename : include/elemental/graphics/complex_display_window_decl.hpp => include/elemental/io/complex_display_window_decl.hpp
rename : include/elemental/graphics/display_widget_decl.hpp => include/elemental/io/display_widget_decl.hpp
rename : include/elemental/graphics/display_widget_impl.hpp => include/elemental/io/display_widget_impl.hpp
rename : include/elemental/graphics/display_window_decl.hpp => include/elemental/io/display_window_decl.hpp
rename : include/elemental/graphics/spy_widget_decl.hpp => include/elemental/io/spy_widget_decl.hpp
rename : include/elemental/graphics/spy_widget_impl.hpp => include/elemental/io/spy_widget_impl.hpp
rename : include/elemental/graphics/spy_window_decl.hpp => include/elemental/io/spy_window_decl.hpp
rename : include/elemental/graphics_decl.hpp => include/elemental/io_decl.hpp
rename : include/elemental/graphics_impl.hpp => include/elemental/io_impl.hpp
rename : src/graphics/ComplexDisplayWindow.cpp => src/io/ComplexDisplayWindow.cpp
rename : src/graphics/DisplayWindow.cpp => src/io/DisplayWindow.cpp
rename : src/graphics/SpyWindow.cpp => src/io/SpyWindow.cpp