Added iterable objects

__iter and __next are now reserved IStrings, OP_NEXT and OP_ITER have also been added. A new token (TOKEN_IN) has been added to the lexer. The parser now supports the for each loop (for i, ... in <object> do ... end).
savedPushed has been removed from the CCompilerState struct.

src/cdebug.c

@@ -132,6 +132,10 @@ int disasmInstr(CChunk *chunk, int offset, int indent) {
             return simpleInstruction("OP_SETOBJECT", offset);
         case OP_INVOKE:
             return u8u8OperandInstruction("OP_INVOKE", chunk, offset);
+        case OP_ITER:
+            return simpleInstruction("OP_ITER", offset);
+        case OP_NEXT:
+            return u8u16OperandInstruction("OP_NEXT", chunk, offset);
         case OP_ADD:
             return simpleInstruction("OP_ADD", offset);
         case OP_SUB: