Added scopes using '{}' symbols, read more

I've also added a new literal type called 'identifier'. This will be
used for variable names, and has a type mask embedded in it.

source/opcodes.h

@@ -20,6 +20,8 @@ typedef enum Opcode {
 	OP_MODULO,
 	OP_GROUPING_BEGIN,
 	OP_GROUPING_END,
+	OP_SCOPE_BEGIN,
+	OP_SCOPE_END,
 
 	//meta
 	OP_SECTION_END,