COMMON: add CGA b/w render mode

(for SCUMM v1)

common/gui_options.cpp

@@ -63,7 +63,8 @@ const struct GameOpt {
 	{ GUIO_RENDERHERCGREEN,		"hercGreen" },
 	{ GUIO_RENDERHERCAMBER,		"hercAmber" },
 	{ GUIO_RENDERCGA,			"cga" },
-	{ GUIO_RENDERCGACOMP,		"cgacomp" },
+	{ GUIO_RENDERCGACOMP,		"cgaComp" },
+	{ GUIO_RENDERCGABW,			"cgaBW" },
 	{ GUIO_RENDEREGA,			"ega" },
 	{ GUIO_RENDERVGA,			"vga" },
 	{ GUIO_RENDERAMIGA,			"amiga" },

common/gui_options.h

@@ -60,6 +60,7 @@
 #define GUIO_RENDERMACINTOSH	"\x23"
 #define GUIO_RENDERMACINTOSHBW	"\x28"	// Setting this to 0x28 is not ideal, but there is no free slot left. Maybe we need to migrate to 3-digit numbers...
 #define GUIO_RENDERCGACOMP		"\x29"
+#define GUIO_RENDERCGABW		"\x2a"
 
 #define GUIO_LINKSPEECHTOSFX "\x24"
 #define GUIO_LINKMUSICTOSFX  "\x25"

common/rendermode.cpp

@@ -35,6 +35,8 @@ const RenderModeDescription g_renderModes[] = {
 	{ "hercAmber", _s("Hercules Amber"), kRenderHercA },
 	{ "cga", "CGA", kRenderCGA },
 	{ "cgaComp", "CGA Composite", kRenderCGAComp },
+	// I18N: CGA black-and-white
+	{ "cgaBW", "CGA b/w", kRenderCGA_BW },
 	{ "ega", "EGA", kRenderEGA },
 	{ "vga", "VGA", kRenderVGA },
 	{ "amiga", "Amiga", kRenderAmiga },
@@ -72,6 +74,7 @@ static const RenderGUIOMapping s_renderGUIOMapping[] = {
 	{ kRenderMacintosh,		GUIO_RENDERMACINTOSH },
 	{ kRenderMacintoshBW,	GUIO_RENDERMACINTOSHBW },
 	{ kRenderCGAComp,	    GUIO_RENDERCGACOMP },
+	{ kRenderCGA_BW,	    GUIO_RENDERCGABW }
 };
 
 DECLARE_TRANSLATION_ADDITIONAL_CONTEXT("Hercules Green", "lowres")

common/rendermode.h

@@ -58,7 +58,8 @@ enum RenderMode {
 	kRenderAtariST = 11,
 	kRenderMacintosh = 12,
 	kRenderMacintoshBW = 13,
-	kRenderCGAComp = 14
+	kRenderCGAComp = 14,
+	kRenderCGA_BW = 15,
 };
 
 struct RenderModeDescription {