Clarify disabled characters in program expression

Jan Breuer

2015-09-10 39b7fbcb39edade740feb182c86cb43a43942cb7

 libscpi/src/units.c

@@ -38,6 +38,7 @@
#include "scpi/parser.h"
#include "scpi/units.h"
#include "utils_private.h"
#include "scpi/utils.h"
#include "scpi/error.h"
#include "lexer_private.h"