first incomplete pass at options

layout is done, need to polish up the frontend and emulator options and sort out the mess of input overrides

src/minarch/overrides.h

@@ -0,0 +1,23 @@
+#ifndef OVERRIDES_H
+#define OVERRIDES_H
+
+typedef struct OptionOverride {
+	char* key;
+	char* value;
+	int disable; // hides from user
+} OptionOverride;
+
+typedef struct ButtonMapping { 
+	char* name;
+	int retro;
+	int local;
+} ButtonMapping;
+
+// TODO: not strictly overrides anymore...
+typedef struct CoreOverrides {
+	char* 			core_name;
+	OptionOverride* option_overrides;
+	ButtonMapping* 	button_mapping;
+} CoreOverrides;
+
+#endif